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Development of Analysing Tools and Automatisation - KATRIN

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1. NUT Karlsruher Institut f r Technologie Development of Analysing Tools and Automatisation of Run Control for KATRIN Diplomarbeit von Norman Hau mann An der Fakult t f r Physik Institut f r Experimentelle Kernphysik IEKP Erstgutachter Prof Dr Guido Drexlin Zweitgutachter Prof Dr Wim de Boer Betreuender Mitarbeiter Dr Klaus Schl sser Zweiter betreuender Mitarbeiter Dr Joachim Wolf Bearbeitungszeit 15 M rz 2012 14 M rz 2013 KIT Universit t des Landes Baden W rttemberg und nationales Forschungszentrum in der Helmholtz Gemeinschaft www kit edu Erkl rung Hiermit versichere ich die vorliegende Arbeit selbst ndig verfasst und alle dem Wortlaut oder Sinn nach entnommenen Inhalte anderer Werke an den entsprechenden Stellen unter Angabe der Quelle kenntlich gemacht und keine weiteren Hilfsmittel verwendet zu haben Norman Hau mann Karlsruhe 14 M rz 2013 Zusammenfassung Im Jahre 1930 hatte Wolfgang Pauli die Idee ein Teilchen einzuf hren welches die beim B Zerfall beobachtete scheinbare Verletzung der Erhaltungss tze f r Energie Impuls und Drehimpuls erkl ren kann Paulis Ansatz eines Dreik rperzerfalls durch Postulierung eines neutralen Partikels er nannte es Neutron f hrt auf ein kontinuierliches Elektronen spektrum so wie es beobachtet wird ohne das Erhaltungss tze verletzt werden Allerdings hat Pauli angenommen dass sich dieses Teilchen im Kern be
2. K 32 Pt 30 5 Frequency 2 3 8 o 198 5 198 197 5 197 196 5 196 Voltage EnergyHistograms HistogramR158542S0 Entries Mean RMS 17400 17500 17600 17700 17800 17900 Voltage Figure 5 3 Raw Data analysis of run 158542 with createfilterspec On the left side the filterspectrum is plotted with the count rate Hz on the y axis and the voltage V on the x axis The header shows the run number the scanned line and the used source On the top right is the pulser spectrum Towards higher voltages x axis on can see that the less electrons reach the detector in the filterspectrum and in the pulserspectrum the frequency y axis converges towards the set value of 200Hz Also the highest rate in the filterspectrum corresponds to the lowest rate in the pulserspectrum In the bottom right all energy histograms are plotted On the y axis are the counts and on the x axis the ADC value The red triangles are caused by TSpectrum and show the found peaks the green lines are the integration boundaries The peak on the right is the pulser and the peak on the left is the ROI Region of Interest This histogram is plotted to cross check the data 48 6 Line Position Stability during KATRIN Measurements The main task of the monitor spectrometer in KATRIN is to enable a voltage monitoring of the retarding potential on the Main Spectrometer on a nuclear standard Therefore the monitor spectrometer needs to be able to gu
3. unpublished 2012 Online Available https fuzzy fzk de bscw bscw cgi d752519 Offline 20Analysis 20 KaLi pdf F Harms Assembly and First Results of the KATRIN Focal Plane Detector System at KIT 2012 Diploma Thesis Karlsruhe Institute of Technology Private Communication 2013 M A Howe G A Cox P J Harvey F McGirt K Rielage J F Wilkerson and J M Wouters Sudbury Neutrino Observatory Neutral Current Detector Acquisition Software Overview 2004 Online Available http ieeexplore ieee org xpl articleDetails jsp arnumber 1311985 64 Bibliography 65 Hel13 H t12 How13 HRRO3 Kat05 KKZ97 KUAtO Mel12 Moro3 PRSZ09 Sch97 Sch11 Sle12 Stul2 Th 07 Web12 Wie12 Zboll Helmholtz Zentrum Potsdam Deutsches GeoForschungsZentrum Website 2013 Online Available http www app3 gfz potsdam de Declinationcalc declinationcalc html M H tzel Simulation and analysis of source related effects for KATRIN Ph D dissertation Karlsruhe Institute of Technology 2012 M Howe About Orca 2013 Online Available http orca physics unc edu markhowe Orca_Help About_Orca html A Haungs H Rebel and M Roth Energy spectrum and mass composition of high energy cosmic rays Reports on Progress in Physics vol 66 no 7 p 1145 2003
4. IPE Kali KATRIN KDBServer LFCS MAC E Filter MVC ORCA PCS ROI SLT WGTS ZEUS Advanced Data Extraction Interface compact Field Point Cryogenic Pumping Section Differential Pumping Section Earth Magnetic Field Compensation System First Level Trigger Focal Plane Detector Human Machine Interface Institut fiir Prozessdatenverarbeitung und Elektronik KATRIN Library KArlsruhe TRItium Neutrino KATRIN Database Server Low Field Correction System Magnetic Adiabatic Collimation with an Electrostat Filter Model View Controller Object oriented Real time Control and Acquisition Process Controll System Region Of Interest Second Level Trigger Windowless Gaseous Tritium Source ZEntrale datenerfassung Und Steuerung 61 Bibliography At12 AA 13 AAA 11 ACCT 12 Bill 2 BPG04 CDD 98 Cha32 CHH 99 Chi13 CRH 56 Day07 DGG 62 J F Amsbaugh et al Prototype focal plane detector system for the KATRIN experiment 2012 Online Available https fuzzy fzk de bsew bsew cgi 706270 FPD_System_Prototype_Jan2012 pdf Abe Aberle et al First Measurement of 013 From Delayed Neutron Capture on Hydrogen in the DoubleChooz Experiment 2013 Online Available http arxiv org abs 1301 2948 Aharmim Ahmed Anthony et al Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory 2011 Online Available ht
5. Numbers are hard coded Additionally the download has to be done just one time for a complete run with sub runs As the mean voltage and their standard deviation for three sensors x y z need to be calculated it can take some time That is the reason for the ability to deactivate this read out in the parameter file As nothing should be changed at the sources during one run the program outputs an error if the standard deviation is higher than 0 1 For each line scan it is also very important to know which source has been used To automatise this readout the calibration database is used As it is possible to put four sources into the source holder at one time an efficient method is required to read the sources out After each re inserting of sources a calibration has to be done In four channels the x and y coordinates of each source as well as an error on these have to 45 46 5 Data Analyis Software be written In another four channels each source holder position needs to be identified to its source Overall this has the advantage that this has to be done once until the source chamber is opened again and something has been changed on the source holder The error on the coordinates is necessary because the positions are only reproducible within a certain tolerance For old data it has not been possible to use this method Thus each source was included manually with a validation time stamp Now all sources are included in the database since
6. Online Available http dx doi org 10 1088 0034 4885 66 7 202 Katrin Collaboration Katrin Design Report 2004 2005 H V Klapdor Kleingrothaus and K Zuber Teilchenastrophysik mit zahlreichen Tabellen ser Teubner Studienb cher Physik Stuttgart Teubner 1997 Online Available http www gbv de dms goettingen 22727833X pdf Kodamaa Ushidaa Andreopoulosb Saoulidoub Tzanakosb et al Obser vation of tau neutrino interactions sciencedirect 2001 Online Available http dx doi org 10 1016 S0370 2693 01 00307 0 M Meloni Private communication 2012 M Morhac Processing and Visualization Functions 2003 Online Available ftp root cern ch root Spectrum doc B Povh K Rith C Scholz and F Zetsche Teilchen und Kerne Eine Einf hrung in die physikalischen Konzepte Berlin Heidelberg 2009 Online Available http dx doi org 10 1007 978 3 540 68080 2 N Schmitz Neutrinophysik mit 28 Tabellen ser Teubner Studienbiicher Physik Stuttgart Teubner 1997 Online Available http www gbv de dms goettingen 227563085 pdf M Schupp Inbetriebnahme des Monitorspektrometers und erste Messungen 2011 Diploma Thesis Karlsruhe Institute of Technology M Slezak Fit program of the KATRIN Monitor spectrometer User s manual 2012 Online Available https nuserv uni muenster de
7. September 2011 and can be read out automatically for older runs also Visualisation of Data After all data for one line scan are derived and calculated createfilterspec is able to plot the data One example can be seen in figure 5 3 This output enables the user to detect possible problems during the analysis or the line scan On the left side is the filterspectrum on the top right the pulserspectrum and in the bottom right all energy histograms with the peaks found red triangles and the used integration boundaries green lines To take a closer look at data it is also possible to zoom into these graphs The header of the filterspectrum shows the run number the line position and the used source If the user does analyse more than one scan at a time createfilterspec is able to plot the output data for all of them as long as these are runs with sub runs But it is recommended to deactivate the drawing function in the parameter file because it does require a lot of calculation time Storing of Data The output data is stored into a ROOT file The home folder of createfilterspec includes a filterspecdata sub folder After a run is analysed another folder within this sub folder named according to the conversion line is created If the folder already exist the data is just saved within that existing folder The file is named after its run numbers The advantage of ROOT files is that they are small easy to access and with the TBrowser
8. If tritium decays the electrons are guided adiabatically to the tube ends The applied magnetic field is 3 6T and the WGTS will deliver 9 5 10 6 decays per second The tritium that reached the outer regions is pumped in an inner loop by turbomolecular pumps DPS1 R F and is re injected The injection rate per second is 1 7 10 Bq which equals 40g of tritium per day The tritium that cannot be pumped out reaches the transport section either in the front or in the back If it reaches the back it enters the DPS2 R that consists of two pumping ports to protect the Calibration and Monitoring System CMS from too high partial tritium pressure The tritium pumped out enters the outer loop and is not re injected immediately The CMS will consist of electron detectors to measure the electron flux and of electron guns 3 1 2 Transport Section The tritium that took the opposite direction and did not escape through DPS1 F enters the transport section It is desired that the maximum tritium flow rate into the pre spectrometer is of the order of 10 mbarl s This is necessary to reduce the electron background induced by tritium that decays in the spectrometer It must be less than 10 counts s Hence the flux of tritium from the WGTS outlet to the pre spectrometer has to be suppressed by a factor of 10 The transport section is split into two components the DPS and CPS see figure 3 3 The flux of tritium is reduced by about 10 in the
9. KDBServer that is an integral part of the KATRIN DataProcessor is realised with XML files The access to the run files is granted from the same IPE server The MAC on which ORCA is installed is using the RSynd protocol to synchronize run data between the MAC and the harddrives within the IPE server At the monitor spectrometer a RSync protocol is checking for new run files every minute When new run files are uploaded to the Ihttp rsyne samba org 41 42 5 Data Analyis Software Katrin Network MSSQL PCS7 IPE Server Replicated MSSQL L ADEI Katrin DataProcessor PHP Service C Webservice Katrin Numbers Calibration Harddrives Sensors SQL RAID eis Kasper Database Webbrowser KaLi amp Beans Webbrowser Figure 5 1 Overview of the server structure for data analysis of KATRIN The data chain can be splitted into three parts The first is the data recording in the KATRIN network then it is derived by the IPE server and made accessible for the user via web browser or Kasper The figure is adopted from Haa12 IPE server a script is started that executes ORCARoot which transforms the ORCA run files to ROOT files The KATRINDataprocessor is able to access the run data via KDBORCA The IPE server does have an additional SQL database this database contains the different KATRIN numbers their ca
10. Status and the Setup Drawers In the Setup Drawers the Run Number and Run Type can be specified In the top right is the Sub Run Control where the user can start and stop new sub runs manually Below are the Run Options the user can add start and stop scripts and chose offline or normal runs 69 70 Appendix fF Figure A 2 Data Readout Task The FLT card has to be included here to enable Orca to read data eas MultiPlots C Write IGOR Histograms Ship Final Histograms O Accumulate Clear Counts Fler File Figure A 3 Data Monitor The user can take a look at the data that is read out immediately with this object 70 A Orca 71 AAA Data File FileName Status Not Running Size U Limit Size to 10 MB If size limited and limit reached then Stop Run Restart Run File Prefix MonSpec v Prepend Date C Generate MD5 Checksum v Use YY MM Folder Structure Copy Delete Send Queue Data NO NO Idle Status NO NO Idle Config NO NO Idle Stop All v Save Configuration Snapshot Process Limit 50 Data Folder MoSpec 2013 01 Data Logs Folder MoSpec 2013 01 Logs Config Folder MoSpec 2013 01 Configurations Ey Set File Locations and Send Options Figure A 4 Data File The user can chose where to save all the output data The structure of the output files can be edited within this object as well 71 Monitor Spectr
11. The neutrino oscillation in dependence of L E In this figure sin is chosen to be 0 83 The area a shows L E for no oscillation b oscillation and c average oscillations This figure is taken from Zub04 page 198 Double Chooz January 2013 AAT13 sin 2013 0 097 0 034 stat 0 034 syst 2 36 Daya Bay November 2012 Web12 sin 2013 0 089 0 010 stat 0 005 syst 2 37 RENO May 2012 ACCT12 sin 2013 0 113 0 013 stat 0 019 syst 2 38 2 4 The Neutrino Mass From the neutrino oscillations we know that the neutrinos have mass This has a huge im pact on the standard model as it assumes a zero mass for neutrinos Overall the neutrino mass has an extensive influence on cosmological models as the structural development of the universe Although neutrinos interact weak and gravitational only there are so many of them that the mass has an influence of the structural development This can be seen on the left side of figure 2 6 There are two methods of neutrino mass measurements On the one hand model dependent and model independent measurements on the other hand In this section an introduction to both methods is given 12 2 4 The Neutrino Mass 13 10 quasi degenerate CET ee v masses 1071 10 10 hierarchical i v masses 10 0 1 10 140 40 m eV Figure 2 5 The neutrino mass eigenstates in dependence of m On the x ax
12. a heaviside function but in reality it is smeared out by AF According to equation 3 2 and considering the tritium endpoint 18 6keV the main spec trometer has a resolution of AE 0 93eV 3 3 It is also possible to suppress electrons with a large scattering probability long path in the source This is done with a magnetic field Bg see figure 3 6 that is 3 6T and hence lower than Bmax with 6T This magnetic mirror works the same way as the spectrometer from the analysing plane to the second solenoid The perpendicular momentum increases and if the maximum is reached the electron is rejected This leads to a maximal acceptance angle of Bs Max 50 77 3 4 sin Omar 22 3 3 High Voltage Monitoring 23 tT If Erz WER Ba B max D electrodes T source detector without E E field He AL Figure 3 6 Working principle MAC E Filter In the top left an electron entering the MAC E Filter can be seen red The blue lines show the magnetic field produced by the two superconducting solenoids in the very left and right The electron is performing a cyclotron motion caused by the magnetic field In the center the analysing plane the cyclotron motion subsided and the electron may jump over the electrostatical barrier U and can be re accelerated again In the bottom of this figure the behaviour of the perpendicular momentum can be seen This figure is
13. a i DAQ ini er IPE DAQ V4 crate Ve aa ay FLT SLTFLT IPE Simulation SLT FLT SLT FLT Catalog Data Flow Host Vme CAMAC IPE DAQ cPCI PXI HV GPIB USB Serial Ethernet Motors Misc Process Experiments ER ET Monitor Spectrometer q Prespectrometer aS a 29 BAM Detector SNO Ncd Katrin nTPC MAJORANA SNOLab nEDM Figure A 9 The Orca catalog In this figure two tabs of tha catalog are show In the top an overview of IPE objects and in the bottom an overview of the Katrin experiment objects These objects can be dragged and dropped to the experimental setup 74 A Orca 75 A 2 Orca Script library package functions at the Monitor Spectromter set VoltageVessel_V val This function needs an argument and puts the desired voltage on the High Voltage Power Supply for the vessel immediately queue Voltage Vessel_V val This function puts the set values into a queue that still needs to be send set Voltage Vessel kV val This function does the same as set VoltageVesselV_V except the argument has to be in kilovolts queue Voltage Vessel_kV val Puts the set value into a queue but the argument has to be in kilovolts set VoltageSource_V val The argument defines the set voltage on the source queue VoltageSource_V val This function puts the set value into a queue queueCurrent LineNumber val Puts the line number into a queue This is retreived from the Run List a
14. and the red squares measurements without 50 6 2 Least Required Measurement Time 51 The outcome of these measurements show that measurements with varying source po tential do work The weighed mean values are Px32 17829 140 V 0 005 V 6 1 Pra2 17829 123 V 0 006 V 6 2 P132 30477 460 V 0 004 V 6 3 Pr32 30477 452 V 0 002 V 6 4 The difference in line position is less than 20mV for both line positions On the one hand this result is still better than KATRIN requirements but on the other hand further measurements with varying source potential are required By taking measurements with source potential two additional uncertainty factors do occur These are the power supply and the voltmeter The voltmeter used for these measurements is a 6 5 digit voltmeter with a resolution of ImV within the required 1000V range Additionally this voltmeter is not calibrated In future measurements a 8 5 digit voltmeter that is calibrated on a regular basis will be used to measure the source voltage It is also necessary to perform more line scans to reduce the influence of statistical fluc tuations These can be seen in figure and also These measurements have proven that the KATRIN measurement principle for the monitor spectrometer does work 6 2 Least Required Measurement Time To optimise the measurement mode of the monitor spectrometer it is important to make line scans as effective as possible A line scan is do
15. because an experimental setup may use many objects of the same kind for instance several scripts or pulser objects This script also accesses the Run Control to check whether the Run State is set to Normal Run to prevent unrecorded measurements 3 findChanOfControl arg1 path arg2 This function shows how to access any Object defined by find The variable in this case ADEI has to be put in brackets and the function after one space charac ter ADEI findChanOfControl The possible functions for each object can either be found in the source code or by clicking the ORCAScript Quick Guide button this opens another windows showing general scripting hints In the bottom of this window a classname can be entered the classname is just the name of the object This lists all available functions which is usually the fastest possibility to find desired functions Unfortunately there are no deeper descriptions available which makes it necessary to take a look into the source code sometimes Especially when using findChanOfControl function the script wants to find a chan nel in the IPE Slow Control object For this script the channel has to be dragged and dropped previously to that object or it cannot be accessed The function requires two arguments the first one is the ADEI control address and the second one is the path on that machine to the desired control channel It is very important to take care that only MACs have
16. capture pte n ie 2 10 Depending on its mass afterwards a neutron star or a black hole remains A neutron star is very hot and not transparent to photons Thus the energy is released by pair production et e gt n T 2 11 5 Mon amp 1 5Msun 8 2 Neutrinos and l can be any of the three neutrino generations e 1 7 Usually 10 neutrinos arise from such a supernovae So far only the neutrinos of one supernova 1987A in the Large Maglanic Cloud have been observed see KKZ97 pages 391 405 2 2 4 Solar Neutrinos SuperK SNO Gallium Chlorine 22 1012 10 Bahcall Pinsonneault 2004 1010 10 108 107 10 Neutrino Flux 108 104 10 10 1 10 0 1 0 3 1 3 10 Neutrino Energy MeV Figure 2 3 The solar neutrino spectrum On the y axis the neutrino flux can be seen and on the x axis the neutrino energy The Be is the ppII process and 8B the pplII process It shows the originated neutrinos from the pp and CNO cycle with the corresponding energy and flux This figure is taken from BPGO04 Stars derive their energy from nuclear fusion The equation is 4p gt tHe 2e 2ve 26 73MeV 2 12 This can be reached by the pp cycle and the CNO cycle For stars with lower temperatures about the temperature of the sun the pp cycle is dominant and for higher temperatures the CNO cycle Within the pp cycle neutrinos are produced by the following reactions p
17. case of the monitor spectrometer respon sible to read six channels five are used for the detector and and one channel is reading a pulser from one FLT card and transfer the data to ORCA via the SLT card The IPE Slow Control object enables the user to write data to ADEI control which is necessary to perform slow control with ORCA Within that object the user has to enter the ADEI address and derive the sensor and control channels from it Now the user is able to select sensors for just reading values or control channels by setting values The channels can be dragged and dropped to the IPE Slow Control object Read only channels are marked in blue writable control channels in red There will be a more extensive explanation of slow control in the next section 4 2 Overview of the Server System As the KATRIN experiment requires a lot of sensor and controller data an elaborate server system is required An overview in case of the monitor spectrometer is given in figure 4 2 All components in this figure are within the KATRIN network On the left side of this figure the ORCA slow control data chain is shown The slow control data is send from ORCA to ADEI Advanced Data Extraction Interface control which is a Linux server This data is forwarded to ZEUS ZEntrale datenerfassung Und Steuerung At the moment there are four different ZEUS servers at the KATRIN experiment one for the detector the high voltage the air coils and one
18. cgit cgit cgi MoS_ fitter git M Sturm Collaboration Meeting XXIII Fall 2012 Session 02 Main Compo nents New concept for the differential pumping section unpublished 2012 T Th mmler Pr zisions berwachung und Kalibrationder Hochspannung fiir das KATRIN Experiment Ph D dissertation Universit t M nster 2007 D M Webber An Improved Measurement of Electron Antineutrino Disappearance at Daya Bay 2012 Online Available http arxiv org abs 1211 1609 V Wiedmann Systematische Untersuchungen zur Hochspannungsstabil isierung am KATRIN Monitorspektrometer 2012 Diploma Thesis Karlsruhe Institute of Technology M Zboril Solid electron sources for the energy scale monitoring in the KA TRIN experiment Ph D dissertation Universit t M nster 2011 65 66 Bibliography Zub04 K Zuber Neutrino physics ser Series in high energy physics cosmology and gravitation Bristol u a Inst of Physics Publ 2004 includes bibliographical references and index 66 List of Figures 2 1 Overview neutrino sources 2 2 2 2 2m ann 2 2 Air shower caused by cosmic radiation 2 22 22 2 3 Solar Neutrinos s ss e Sn ha an A wR EE eA ee we Ga ai 2 4 Neutrino Oscillation oaoa a 2 5 Neutrino Mass Eigenstates ooa a 2 6 Energy Density 2 22 2 2m om 27 Mass parabola a Be ee aa an au nen es 2 8 Tritium electron spect
19. directly on the flank The first possibility enables reliable long term measurements and stability of the voltage within the KATRIN requirements The second one enables the experimenter to spot changes of the voltage almost immediately In this section some problems and solutions are discussed 6 4 1 Accuracy and Precision of Set Values Hand in hand with the investigation of the reliability of slow control measurements for the accuracy and precision of the set values have been done For the vessel voltage these can be seen in figure 4 4 on page 39 and for the source voltage in figure 4 5 on page 40 For the vessel voltage the accuracy of data points only at about zero are considered as the other values are caused by slow control problems The trend of the plot does look like a triangular voltage with a period of about 5000V Hence the power supply does have different calibrations for different voltage regions The maximum offset between the mea sured and the set values below 28000V is 1V At higher voltages the offset can even be up to 5V Thus the accuracy of that power supply can be increased by a software calibration The width of the plot shows the precision of the power supply The precision is about 0 5V This can partly be explained by temperature fluctuations but the overall precision of the power supply is not very high This cannot be fixed by software For the source power supply only the black circles are considered This measurem
20. equal to the expected flux and proves neutrino oscillations see AAA 11 Hand in hand with the discovery of neutrino oscillations comes the insightful that the lep ton count of one family cannot be conserved and it is necessary that the neutrino flavours do have different masses and at least one flavour has to have a non vanishing mass This is in contrast to the standard model which is not valid in this case and has to be extended The oscillations can be described phenomenologically The flavours v with a e u T and vg Va dag can be described through their mass eigenstates va gt Vai vi vi Sout lela U i Va 2 24 with a unitary mixing matrix U The time dependence of the eigenstates can be described in the following way vi e t e v4 ax 0 2 25 The transition probability of one flavour to another can be calculated P a B t valt lve t 2 26 gt gt UaU UG Upe 2 27 5 vats WS Uri U4 UN 2 28 j gt t 2 L gt UnU 28 I Uai Uk UR Upe T 2 29 j gt i using CP invariance the formula simplifies to Am2 L 2 Ue j ij FAIRE 2 Unljl lg COS 5 z 2 30 j gt i Am 2 L 2 i bog 4 2 UxiUajUpiUg sin i 2 z 2 31 J gt 10 2 3 Neutrino Oscillations 11 with Am m m and L ct By taking a look at just two neutrino flavours the transformations can be described by the Cabbibo matrix Ve _ cos sind vi s u sin cos A 1
21. events in the read out electronics But for high rates the shaping length has to be decreased to have a higher detection rate This is still a problem for the planned electron gun measurements with the detector as these have a high frequency 100kHz and require a high energy resolution An overview of the FPD can be seen in figure 3 4 and the current status of the wafer and its pixels in figure 3 5 3 2 MAC E Filter In principle it is sufficient to generate an experimental setup with a retarding potential that isolates the electrons from the tritium beta decay at the endpoint from lower energy electrons But as the electrons are emitted isotropically a high activity source would be required and the measurement time would still be long The solution is the MAC E Filter that enables an acceptance angle of up to 27 Furthermore there is a lot of experience with the MAC E Filter as it was already used in Mainz and Troitsk Both used the beta decay to derive an upper limit for the neutrino mass These experiments are a solid basis for KATRIN and showed that the MAC E Filter measurement principle works The MAC E Filter consists of two superconducting solenoids These create an inhomoge nous magnetic field which has its maxima in the center of the solenoids and a minimum in the analysing plane between both solenoids In case of the main spectrometer the solenoids have a magnetic field of 4 5T with a maximum of 6T and in the analysin
22. for the monitor spectrometer These ZEUS servers are running on Windows XP and consist of three components The HMI Human Machine Interface proxy that enables ADEI control to communicate with ZEUS and the HMI which is able to read and derive set values from a web interface The connection to thecFP compact Field Point is established by the third component the ZEUS engine It enables to set values to the cFP and read sensor data The cFP is running on VxWorks has a network controller and an eight slot backplane A 12 At the monitor spectrometer the cFP is communicating to the high voltage power supplies and the voltmeter It is planned to integrate the air coil control also The set values and current values read by the field point are stored into a MSSQL Microsoft Structured Query Language database via ZEUS 4 3 Run Control of the Monitor Spectrometer Initially a LabVIEW program written by Michael Schupp Sch11 was used for Run Con trol It was running on a Windows machine in the monitor spectrometer building and Central DAQ and Control System 32 4 3 Run Control of the Monitor Spectrometer 33 Orca ADEI Control Webbrowser HMI proxy gt MSSQL ZEUS engine Air Coil control MeO HV readout Figure 4 2 Overview of the slow control server structure at KATRIN On the left hand side this figure shows the data flow of slow control values from ORCA t
23. is very low it is important to have an effective background suppression and sufficient en ergy resolution Through the segmentation of the detector it is possible to derive the x and y coordinates of an electron and thus calculated its origin which enables background suppression of particles outside the flux tube Additionally veto systems are installed to remove further background The high energy resolution is not necessary for measuring the actual energy of the elec trons from the beta decay this is done by the filter voltage on the main spectrometer but to discriminate background even further It is expected that there will be a continuous background in the desired range of the detector 5 50keV induced by betas and gam mas This could harm the sensitivity of KATRIN and therefore an energy resolution of 20 3 2 MAC E Filter 21 To DAQ Pulse Tube Cooler Veto Panels and Shields Calibration Sources __ 1 gt ewaor Magnet J gt x Gate Valve Pinch Magnet gt Post Acceleration Electrode Figure 3 4 The Focal Plane Detector and the Detector Wafer On the left the FPD with its components can be seen and on the right side the wafer with its detector segments The figures are taken from Har12 AE lt 600eV FWHM is desired High energy resolution at high rates is difficult to realise To determine the energy of one event it is useful to increase the shaping length for these
24. old runs For the sub run mode a new raw data analysis program was writ ten that fulfills all requirements for the monitor spectrometer and can easily be combined with the fit program In future this program can work autonomous on an IPE server and the user can download the output ROOT files containing all necessary data 59 60 7 Conclusion Sub runs due to saving of all histograms enable a detailed look into single runs This was done to check the dependence of the run length and the error on the line position In com bination with the source activity it can be stated that the measurement time multiplied with the source activity may not be lower than 16100kBas for an error below 20mV This means that a source of 1MBq requires about 16s of measurement time per measurement point to derive an error below 20mV on the line position It should be noted that the transmission of the monitor spectrometer is just 53 which is already included in that calculation This leads to a netto measurement time of 160s for 10 measurement points Furthermore temperature fluctuations influence the high voltage system A change of 1 C at 18000V leads to a shift of 100mV on the high voltage system Hence the air condition ing and heating system influences the high voltage but it has been shown that the time intervals per measurement point are too short to directly influence the line position 60 Glossary ADEI cFP CPS DPS EMCS FLT FPD HMI
25. org 10 1007 BF01351864 Forschungsgruppe Neutrinophysik Homepage Forschungsgruppe Neutrino physik February 2013 Online Available http neutrino desy de projekte lena M Fukugita and T Yanagida Physics of neutrinos and ap plication to astrophysics with 64 tabl ser Texts and monographs in physicsPhysics and astronomy online library Berlin Springer 2003 includes bibliographical references and index Online Available http swbplus bsz bw de bsz101226632inh htm Gatti Gallinaro Pergolesi et al MARE Microcalorimeter Arrays for a Rhenium Experiment 2006 Online Available http crio mib infn it wig silicini proposal proposal_ MARE_v2 6 pdf Goldhaber Grodzins and Sunyar Helicity of Neutrinos American Physical Society 1958 Online Available http dx doi org 10 1103 PhysRev 109 1015 W Gil Collaboration Meeting XXIII Fall 2012 Session 02 Main Components Status of Cryogenic Pumping Section unpublished 2012 J D Goullon Installation and commissioning of the monitor spectrometer of KATRIN 2010 Diploma Thesis Karlsruhe Institute of Technology A Ghosh T Thakore and S Choubey Determining the Neutrino Mass Hierarchy with INO T2K NOvA and Reactor Experiments 2012 Online Available http arxiv org abs 1212 1305 M Haag Collaboration Meeting XXIII Fall 2012 Session 09 Offline Analysis
26. the double beta decay does exist all energy is with the electrons and a distinct peak is observed From the rate the half time can be obtained and hence the neutrino mass ry x mp 2 42 The mass of the Majorana neutrino can be calculated m mj 2 43 J Unfortunately the matrix element U is necessary and two problems can occur e As Uz can also be negative the m can cancel each other and if an upper boundary for m is found it is not an upper boundary for the mass eigenstates e The neutrinoless double beta decay is only possible if there is at least one Majorana neutrino with m 0 The neutrinoless double beta decay is one example for model dependent experiments as the required nuclear matrix element is model dependent see Sch97 pages 300 306 2 4 2 B Decay The normal beta decay was described by Fermi in the 1930s The decay can be described as follows n gt pte P 2 44 So by investigating the beta spectrum of electrons statements about the absolute neu trino mass can be made The energy spectrum for tritium beta decay electrons looks the following dN ap CF EE mec Ey E E Eo m2 0 Ey E m 2 45 with m mass of the neutrino m mass of the electron E kinetic energy of the electron p momentum of the electron Eo max electron energy m 0 F Z E fermi function G2 step function for energy conservation C E cos dc M T c Cabbibo angle Gr F
27. wants to start a new run a 0 has to be entered into that column and line and for the following sub runs a 1 For OpenOffice a macro and a template is provided which outputs the active sheet in the correct csv format The data is saved in Measurement and the file name is the name of the active sheet Now it can be read by the Run List If the user has done everything correctly it should look like in figure A 7 By clicking the start button all script parameters are sent to a script This script sends the set values for the voltages to ADEI control as well as the current line and run number Afterwards it waits until the set waiting time has passed This marks also a little difference to the old program The waiting time has to be increased a little bit because it includes the time the current value needs to reach the set value When the script is finished the Run List starts a run with its given parameters Usually for the first run the sub run box is not check marked although it does not make any difference for the first run because a new run is started anyways All settings from the crate object are written to the crate at the monitor spectrometer as we are measuring in histogram mode it is very important to check the histogram length on the FLT card The longer they are the smaller the output data becomes which is good in the first place But this has one huge side effect the histogram length influences the measur
28. 0 1000 2000 3000 4000 5000 6000 7000 time s Figure 6 6 Voltage oscillation of the high voltage power supplies at constant voltage split into 100s intervals This figure is equivalent to figure 6 5 and the K 35 divider but the meanvalues of 100s intervals are plotted Addi tionally the standard deviations of these 100s intervals are shown Temperature C 0 1000 2000 3000 4000 5000 6000 7000 time s Figure 6 7 Temperature oscillation in the Monitor Spectrometer building On the y axis the temperature in degrees celsius can be seen On the x axis is the time in seconds This plot shows the read out of a temperate sensor which measures the room temperature 56 6 4 Problems and Solutions 57 9 26 960 oO 5 26 8 7p D 26 7 a 26 6 26 5 26 4 26 3 26 2 26 1 26 0 1000 2000 3000 4000 5000 6000 7000 time s Figure 6 8 Apparent pressure oscillation at the detector On the y axis the pres sure in millibar can be seen On the x axis is the time in seconds The time interval is identical to the previous figures 6 4 Problems and Solutions As the monitor spectrometer is responsible for monitoring the voltage on the main spec trometer it is important to guarantee a stable line position There are two different measuring principles on the one hand usual line scans by changing the source voltage or on the other hand by choosing a voltage that is very close to the line position and
29. 2 32 with the mixing angle 0 The transition probability can be calculated from formula 2 31 and the Cabbibo matrix Am L P ve gt va sin 20 sin Me 2 33 a 4 E From this equation it can be derived that the mixing angle and the mass difference Am cannot vanish if there are neutrino oscillations Hence for oscillations to occur a distance to the source L 4 u EAN E 7 Am is necessary This is essential for neutrino oscillation measurements at reactors For accelerator neutrinos it is possible to influence the energy of the neutrinos but usually high energies are preferred as these have higher cross sections Of course this is just an approximation for two flavours It becomes a little bit more difficult using all three of them This matrix is called the Maki Nakagava Sakata MNS matrix which is a 3 x 3 matrix 2 34 10 12C13 512C13 size 5 5 UMNs 812 23 12823813 C12C93 12823513e 523013 2 35 5 5 312523 12823813e C 2823 12C 23813e C23C13 with sij sin 6 Cij cos 0 j see Zub04 pages 190 196 124 Neutrino oscillation experiments aim to measure the mixing angles and the mass square differences They are not able to measure the absolute mass Latest experiments are the Double Chooz the Daya Bay and the RENO experiment All of them are looking for the mixing angle 013 The Double Chooze experiment is placed at the nuclear power sta
30. A AA Ahi AM Ahd AAA MA AAAA AA A AMAA Aba a Ah Aiii D A a A A a amp a a aa a a a 5 a Ten e gt A AAAA MAMAA A AM AA MA AM MA A AA a A pm a A M Ai A AA A A Ahi aaa A AA a a a c Ak AA A A a a A AAA AA AA A a 2 eee A AA AA A A MAA A A M AAA A A aA A AA u hk a wm A a N aoa MA A AA A AM A Mh Ak A l am Aa A a A a a A AMA A a a RUA EUER A EL EAN EEE AN ZELLE LEN EAN bid Abit Ai AALEN ANAL EEE ULLA BEN ELILHNE ZH Arien 5 A aa a aa pi A A A A A Ah A aA a a a A A A a Pah A AMA AMAA A Ah AAAA Add A A Ai A Adii AAA Ai AAAA AA AAA AMA AA A AAA Ah AAA AAA Adis Adie AA AA A AAAA Aih rm Aa a 10 A A rm A bea a a4 a rm V0 Vw A AAA A aa a ra aaa 15 aa a a a aa 20 1 1 i Ly 1 i 1 1 l 0 200 400 600 800 1000 Voltage V Figure 4 5 The behaviour of the Source Power Supply On the y axis the set voltage current voltage can be seen and on the x axis the set voltage The black circles show a measurement from January 17th till January 19th and the red triangles the measurement on January 20th 40 5 Data Analyis Software The Analysis Software at the monitor spectrometer is splitted into two parts On the one hand the raw data analysis this is done by a program called createfilterspec It is able to connect to the KDBServer KATRIN Database Server through KaLi KATRIN library and derive the slow control data and run files from it On the other hand a fit program ca
31. Ausgabedatei zu spe ichern Zuvor war f r jeden Setzwert ein separater Run notwendig Allerdings haben Sub Runs den Nachteil dass sie mehr Platz ben tigen da alle Histogramme eines Runs gespeichert werden m ssen und ein zuvor benutztes Filterskript nicht mehr verwendet werden kann Momentan gibt es noch Probleme mit der Prozesssteuerung da Setzwerte Endger te nicht erreichen und die Zeit zwischen Absenden des Setzwertes bis zum entsprechen den Istwert sehr lang sein kann e Rohdatenanalyse Im Zuge der Umstellung auf Sub Runs wurde ein neues Analyseprogramm notwendig Es ist in der Lage sowohl alte als auch neue Runs auszulesen die Quellenposition die benutzte Quelle sowie die angelegte Quellspannung zu bestimmen desweiteren kann es Histogramme automatisch analysieren und die ungef hre Linienposition bes timmen Alle Daten werden in einer ROOT Datei gespeichert Dieses kann vom Fit Programm eingelesen werden um die Linienposition zu bestimmen Das Analyseprogramm bezieht die Run Daten ROOT von einem IPE Server sum miert ber alle Histogramme f r einen Sub Run und sucht darin nach Peaks Wenn es die korrekten gefunden hat werden die passenden Integrationsgrenzen bestimmt und es wird ber diesen Peak integriert Das so bestimmte Integral enth lt die Anzahl der detektierten Elektronen und aus der Laufzeit des Sub Runs l t sicht die Detektionsrate bestimmen Aufgetragen ber die entsprechende Spannung pro Messpunkt ergi
32. CA has executed the trailed script immediately as the Run Length timer reached zero This must not happen until the last histogram is received and it has been fixed by Mark Howe 4 5 2 Timestamps After the switch to Run Control with ORCA large errors on the voltage occurred during analysis This has been caused by a time offset between ORCA timestamps and voltage timestamps It turned out that ZEUS had a time offset of ten seconds This is caused by Windows XP that is very inaccurate considering the local PC time An external program called About Time that synchronizes the ZEUS local time every sixty minutes with the local time serve 1 fixed that problem 4 5 3 Slow Control The setting of Slow Control values via ORCA has been very problematic About 30 of set values have been lost on the way to the Field Point with the postControlSetpoint ForChan see section function For every single control channel the values have been set one after another One solution for this has been to write loops in ORCA Script that should wait until each current value equals its set value This was on the one hand very slow as the current value needs some additional time to be written to ADEI On the other hand it is not reliable as the current value read differs from the set value and the offset is not constant see figure 4 4 The final solution is to use queues These are much more reliable and seemed to be the final solution During a test meas
33. DPS2 F through four pumping ports with turbo molecular pumps These have a pumping speed of 20001 s To achieve a sufficient reduction factor the beam line is tilted four times by twenty degrees but the 18 3 1 Main Components 19 pam aee z i G p amp Te S I e m DPS1 R WGTS tube DPS1 F Module 2 Module 1 3 6 T Module 1 Module 2 3 6T l 3 6T 30 K Standard mode 56T 56T 85K 30K 120 K Krypton mode 30K 85K 120K 120K ae 120K 120K I Solenoid T Kr injection chamber Beamtube VI R PP2 R PPI R PPI F PP2 F VI F R Rear system 16m F Forward system Figure 3 2 Scheme of the WGTS In the top the CAD view of the WGTS can be seen and in the bottom a scheme with its components This figure is taken from H t12 electrons do not hit the wall as they are guided by a magnetic field In the CPS the beam tube is cooled down to 4 5K At this temperature the tritium molecules can be adsorbed on the inner tube surfaces The surface is covered by a layer of argon frost and is cooled by liquid helium The beam line in the CPS is tilted also 3 1 3 Pre Spectrometer The pre spectrometer has a length of 3 38m and an inner diameter of 1 68m 1 70m outer diameter and has a cylindrical shape It acts as an electron pre filter All electrons with an energy below 18 3keV are rejected The electrons with an energy above that hurdle can enter the main spectrometer The electron fl
34. File 2 2 2222 Con ee 43 Deriving peak counts from the Energy Histogram 43 Mhe Run Time s 24 26646405 an bee ed adhe 8 hie 45 The Slow Control Datal 2 2 2 om m nn 45 Visualisation of Data 2 2 2 2 on on nn 46 Storing of Data 2 CC aa 46 5 2 2 The Fit Program a a ern deze 46 5 2 3 Outlook e s ke oreo p r edla e aea aa Lp a p E on aa a a 47 6 Line Position Stability during KATRIN Measurements 49 6 1 Measurements with varying Source Potential 49 6 2 Least Required Measurement Time oaa nn 51 6 3 Temperature Dependencies 222 ooa a rn 54 6 3 1 Influence on the High Voltage System 54 6 3 2 General influence on the Monitor Spectrometer 2 2 2 55 6 4 Problems and Solutions 2 2 2 a a 57 6 4 1 Accuracy and Precision of Set Values Bese deck dh wee See ee we he ae a 57 6 4 2 Time Discrepancy 2 0 0 0 2 58 7 Conclusion 59 Glossary 61 Bibliography 63 Appendix 69 AS OTA ha sepa a a en ae eA eek ee ek 69 A 1 Additional Orca graphics 22 22 m Emm mann 69 A 2 Orca Script library package functions at the Monitor Spectromter 75 A 4 Parameter file of createfilterspec Danksagung A 3 Orca Slow Control Script at the Monitor Spectrometer 77 1 Introduction Almost eighty years ago Enrico Fermi developed the theory of the 6 decay as a three body process Fer34 Th
35. all beta unstable isotopes Additionally tritium has a short half life of 12 3 years As tritium and the Het ion do have a simple electron shell configuration atomic corrections can be calculated and through the low nuclear charge Z the inelastic scattering of electrons is small The decay of Tritium looks the following 3H He Le 7 2 47 Rhenium The MARE experiment Microcalorimeter Arrays for a Rhenium Experiment uses the rhenium beta decay 187 Re ITOs e7 7 2 48 The advantage of Rhenium is a very small endpoint energy which is 2 47keV and even smaller than the one of tritium Unfortunately the half time is 43 2 10 years which makes a lot of rhenium necessary for the source GGP 06 16 3 The KATRIN Experiment The KATRIN Experiment Karlsruhe Tritium Neutrino Experiment aims to measure the neutrino mass by measuring the tritium beta spectrum at the endpoint The experiment does not involve nuclear models and will set the neutrino mass to an upper limit of m 0 2eV c 90 C L if no neutrino mass signal can be obtained above the limit This is one order of improvement to previous neutrino mass experiments at Mainz and Troitsk In this chapter an introduction to the individual components of KATRIN is given as well as an explanation of the MAC E Filter as well as an introduction to the high voltage system and the monitor spectrometer To be used as monitor spectrometer the setup from Mainz was installed in Ka
36. arantee a constant line position within a 59mV range per two months Erh12 During KATRIN measurements the same voltage applied on the main spectromter will be applied to the monitor spectrometer As Tritium endpoint measurements do require a voltage of 18 6kV the K 32 conversion electrons need to be accelerated from 17 8kV to 18 6kV This is realised with an accelerating voltage applied directly on the sources Within the switch to ORCA slow control a new power supply was integrated to the Field Point that can be connected to each source individually One part of this thesis is to check whether the source potential does influence the line position Additionally oscillations on the power supplies were observed and the influence on the line positions will be discussed here Using sub runs requires to save every single histogram within the run files But this makes it possible to take a closer look at every single histogram In this chapter a closer look at one run and its single histograms is taken to determine the least required measurement time in dependency of the activity of the source 6 1 Measurements with varying Source Potential In the course of this thesis stability measurements with a varying source potential have been done For the K 32 conversion line the retarding potential was set to 18000V and the source potential was scanned from 150V to 200V Afterwards the voltages were in creased in 150V steps and the scan was done aga
37. as large and there was one measurement point within the run files that could not be explained An explanation is given in this section The monitor spectrometer has also been testing the server structure of the KATRIN exper iment and its reliability It turned out that a lot of improvement considering slow control is still necessary In this section problems and solutions for Run Control are discussed 4 5 1 Sub Runs In the beginning of measurements at the monitor spectrometer no sub runs had been used due to a missing integration of sub runs in Run Control with LabVIEW As Run Control with ORCA had been realised it became possible to use sub runs with the Run List Immediately after the switch of slow control to ORCA sub runs were not used because the Analysis Software had not been ready for it As soon as it became possible to analyse Git is a version control system to handle projects https nuserv uni muenster de cgit cgit cgi ORCARunControl git 36 4 5 Problems and Solutions 37 Script ORRunModel 1 2096 O Name ORRunModel Running O Break Chain C Start With ORCA File Untitled o Start With Run Description C Stop With Run ert functio Re Indent H 2 CE ADEI ORIpeSI LowContro Model 1 ADEI f ind ORIpeSlovControlModel 1 4 ADEI queueControlSetpointForChan VoltageChanvessel value Voltagevessel 5 ADEI sendSetpointRequestQueue Globals Figure Voltageve
38. as to be very high as well A shift of the retarding voltage of 0 05eV leads to systematic error of the fitted neutrino mass of 0 04eV There are no voltmeters that are precise enough to measure 18 6kV directly Commer cially available voltmeters are most precise in the 10V range Therefore a very precise high voltage divider are required For KATRIN there will be two high voltage dividers K 35 and K 65 Th 07 Additionally a second spectrometer will be installed It is based on the MAC F Filter principle as well but this time the requirements on the spectrom eter are different The same voltage applied on the main spectrometer will be applied on this external spectrometer It can validate the voltage stability by means of a nuclear standard That is especially important for long term measurements It is called the mon itor spectrometer There will be an introduction to the monitor spectrometer in the next section 3 4 Monitor Spectrometer As this thesis is mainly based on the work at the monitor spectrometer see figure B 7 a short introduction will be given The retarding voltage on the main spectrometer vessel will be identical to the retard ing voltage on the monitor spectrometer Therefore K 32 conversion electrons from the 838Rb 83 Kr source with an energy of 17 8keV will be accelerated to leap the retarding voltage of 18 6kV Therefrom the line position in dependence on the retarding voltage and accelerating voltage can be deriv
39. at idea originated from Wolfgang Pauli in 1930 originally At that time the continuous 3 spectrum could not be explained Pauli was thinking of an undis covered third particle in the nucleus which he called neutron H This could explain the B spectrum Between the first idea of a neutral particle by Pauli and the theory of Fermi four years passed by meanwhile a neutral particle within the nucleus was found by James Chadwick Cha32 It was called neutron nevertheless it could not explain the 8 decay Fermi s theory introduced a third and this time free particle he called the little neutron neutrino The first experimental confirmation of free neutrinos was in 1956 CRH 56 The neutrino only interacts weakly and gravitational and gravitational if the neutrino is not massless Within the standard model the neutrino is assumed to be massless In the 1960s experiments to measure the neutrino flux from the sun were started A deficit of solar neutrinos was found In the mid 90s it turned out that neutrinos can change their flavour by so called flavour oscillations Hence the neutrinos cannot be massless and there is physics beyond the standard model Since the discovery of neutrinos there is the ambition to measure the neutrino mass As neutrino oscillation experiments cannot measure the absolute mass different experiments are required It can be differentiated between model dependent and model independent experiments A m
40. ation due to temperature oscillation 6 6 Voltage oscillation due to temperature oscillation in 100s parts 6 7 Temperature oscillation in the Monitor Spectrometer building 6 8 Pressure oscillation of the detector sensor 0 0004 A l Run Control oa A 2 Data Readout 222222 ee A 3 Data Monitor aoaaa AA Data Pale es eraga epa eaa a ee a A 5 Monitor Spectrometer object 2 0 ee 67 30 68 List of Figures A 6 Orca Script A 7 RunList A 8 IPE Slow Control object A 9 The Orca catalog 68 Appendix A Orca A 1 Additional Orca graphics Run Control Run Control Sub Run Control Start Run New Run Stop Run End Sub Run New Sub Run dia Run Status Sub Run Timers Run Number 159049 oO Sub Run Elapsed Time Status Stopped Since End of Sub Run Time Started Run Options Elapsed Time nep 5 6z c Tune oie Start Script gt Waits 0 Stop Script Vetos 0 Start Script u C Run 3600 Secs Then Repeat Stop Script Open MN 5 M Setup Drawers U Quick Start C Remote Run Type Normal O Offline Figure A 1 Run Control within Orca In the top left runs can be started and stopped as well as a new run can be started Below is the Run
41. ave an effective Run Control program This task is done by ORCA which is capable to perform the data acquisition and real time control In the course of this thesis ORCA was used at the monitor spectrometer performing Run Control for the first time It was possible to obliterate many problems that occurred But slow control still needs improvement Some set values do not result in their appropriate current value At present the loss of data between ORCA and ZEUS is investigated till now it turned out that there are timeouts from time to time This might be caused by an overload of the server structure and hence the timeout was increased from 200ms to 500ms additionally the connection from the KATRIN to the IPE network will be switched to 1Gbit s as it used to be just 100Mbit s The connection ZEUS cFP and the devices is currently being improved The cFP and its end devices will be put into a separate network to obviate network problems The system will be tested when the monitor spectrometer starts measurements again Overall it needs to be pointed out that Run Control works fine with ORCA and the de veloped ORCA Script libraries will ease ORCA Scripting in future The monitor spectrometer is using sub runs for line scans this decreases the amount of runs but on the other side a filterscript cannot be used which prevented all histograms from being saved in the output file but the last one This makes the output files large in comparison to
42. bt sich das Filterspektrum Die Spannungen werden vom Analyse programm auch von einem IPE Server heruntergeladen vi vi e Stabilit t der Linienposition Um die Linienposition im KATRIN Messbetrieb zu bestimmen ist es notwendig die K 32 Konversionselektronen der Kr Rb Quelle zu beschleunigen damit sie mit ca 17 8keV in der Lage sind die am Haupt und Monitorspektrometer anliegende Retardierungsspannung von 18 6kV zu berwinden Es wurde bereits in vorheri gen Diplomarbeiten gezeigt dass das Monitorspektrometer in der Lage ist eine hohe Stabilit t der K 32 Linienposition zu gew hrleisten allerdings wurden die Elektro nen vorher nicht beschleunigt und die Retardierunsspannung war unabh ngig vom Hauptspektrometer und lag bei ca 17 8kV f r K 32 Konversionselektronen Im Rahmen dieser Diplomarbeiten wurden unterschiedliche Retardierungsspannun gen verwendet und die Beschleunigungsspannung dementsprechend eingestellt Die Differenz zwischen beiden Messmethoden liegt unter 20mV allerdings gibt es noch keine Langzeitmessungen und das verwendete Voltmeter f r die Beschleunigungss pannung wird gegen ein pr ziseres ausgetauscht Desweiteren ist es wichtig die Messzeit f r einen Messpunkt zu optimieren und so ger ing wie m glich zu halten Sub Runs erm glichen es einen Einblick in jedes einzelne Histogramm zu nehmen und so ein Verh ltnis von Messdauer und Fehler auf die Linienposition zu bestimmen Mit Hilfe der Aktivit
43. can drag and 29 30 4 Slow Control of KATRIN gt MonSpec Orca Setup Orca z 4 z ary x 1 gt 7 Cie a x x me Catalog HW Wizard Preferences CommandCenter Print ORCARootService Customize Hardware Finder Status Log Alarm Maste Run SlowControl File Set Voltages manually Initialize Pulser 4 My My Ma Watch DATA I Minicrate ADEI Object Pulse 100 Security Disabled Lock All Ey Figure 4 1 Overview of the experimental setup at the monitor spectrometer in ORCA configuration window Each icon represents a piece of hardware a data acquisition task or an analysis module From this panel the whole measurement can be controlled The numbered areas are described on page 30 drop new objects from the catalog to the experimental setup in the main window A detailed description of the most important objects for KATRIN in the example of the monitor spectrometer see 4 1 follows below The description refers partly to How13 A picture of of each marked object can be found in the appendix ORCA Object Description 1 Run Control A 1 The main function of Run Control is to start and stop a run but it is more powerful than just that The user is able to set Run Numbers to chose Run Types for instance the Run Type Maintenance enables the user to change values which are usually fixed while running These options can be found in the Setup Drawers Additionally
44. command a look into the data can be taken immediately As the pulserspectrum and filterspectrum are saved as TGraphErrors into the root file directly it is not even necessary to plot them again as the TBrowser is able to draw them immediately The fit program for the monitor spectrometer has been changed in a way that it can easily access these output files Within those output files all necessary data for one line scan can be found These are the filterspectrum the pulserspectrum all histograms for each measurement point their integration boundaries as well as the source name the source position and its errors Additionally the line position line name and the time stamps for all runs sub runs It is also possible to output the data into a txt file This enables easier access to the data for the user but just the filterspecdata the time stamps and the source position as well as the used source is saved This is not recommended to be used with the fit program In future this ROOT file should be saved on the IPE server containing the usual run files and enable an easy access to analysed data via KaLi and the ADEI webinterface The webinterface is also able to draw the filterspectrum plots of each run 5 2 2 The Fit Program In the following section an introduction to the fit program is given A lot of information is derived from the manual of the fit program Sle12 The program can be found on the GIT repository y After the prog
45. counts 44 5 2 The Monitor Spectrometer Analysis Software 45 If the createfilterspec is not able to find the correct peaks within one histogram these are skipped to the end After all histograms are available these are summed and the peak search is started within the summed histogram The found peaks and its emanating boundaries are used for the integration of the missing histograms If createfilterspec cannot find any peaks the current histogram is plotted and the program exits Usually this histogram is empty Additionally it is possible to set integration boundaries manually and deactivate the peak search This can be very useful for some measurements but the user has to be careful to set these boundaries very exact as no fitting is done The option for that can be found in the parameter file and the boundaries are set in integrationbound txt The Run Time To calculate rates it is necessary to know the Run Time of one sub run There are several possibilities to derive the Run Time The previous createfilterspec did not use the time stamps that ORCA recorded The problem was that the option Sync with Run Control was not enabled on the FLT card This resulted in wrong time stamps for ORCA run files The solution was to count the histograms of one run and multiply this number with the histogram Length To enable the latest version of createfilterspec to analyse old data the same way of Run Time calculation is used Additional
46. ctrons see figure 5 3 are considered and the highest rate reduced by the background gives the amplitude For the date of the considered run the amplitude is y 3315 1900 This amplitude is an indicator for the K 32 conversion electrons But Ihttp www oxford instruments com 53 54 6 Line Position Stability during KATRIN Measurements the intensity of K 32 conversion electrons is just 17 Zbolll This leads to the following equation Aa I 2315 195 _ 163874 94 Bq 163 87 kB 6 9 me TR O47 20119 en From activity measurements in Rez the back calculated activity is Ameas 309 43 kBq 6 10 This results in a ratio of Acalc _ 163 87 kBq Ameas 309 43 kBq 52 95 6 11 This means that the monitor spectrometer has a transmission of about 53 and the activity has to be about two times higher than the calculated For voltage monitoring it is feasible to use a 30s measurement time per sub run at this ac tivity All huge fluctuations are averaged out and the line position has an offset of maximal 10mV to the position after 62s This enables a fast analysis of the line position but the same statistics if the scan is done twice The problem is the necessary time for slow control between sub runs It does still take too long to use shorter measurement times effectively If there are new sources with activities in the MBq order the required measurement time can be very short and the slow control becomes the
47. ds of the spectrometer in a distance of 2 01m to the analysing plane solenoids are placed At a current of 50A they produce a magnetic field of 6T Therefore they need to be superconducting and to be operated at 4 2K which makes liquid helium necessary To lose as little helium as possible a liquid nitrogen and vacuum shield is installed 3 4 4 Low Field Correction System The task of the Low Field Correction System LFCS is to correct of the magnetic field produced by the two solenoids so that the magnetic field in the analysing plane of the desired 3G is achieved The LFCS consists of four air coils surrounding the spectrometer These can be seen in the top and bottom of figure 3 9 3 4 5 Earth Magnetic Field Compensation System To compensate the magnetic field of the earth the Earth Magnetic Field Compensation System EMCS is installed 26 3 4 Monitor Spectrometer 27 The earth magnetic field in Karlsruhe is 0 5G which is 1 6 of 3G in the analysing plane and has to be corrected 3 4 6 Detector The detector consists of five semi conductor PIN diodes They are arranged like a cross with one central pixel The four outer pixels are Hamamatsu S3590 09 PIN diodes used to align the detector on the spectrometer axis For spectroscopy only the central pixel a Canberra PD150 12 500AM is used The cross is aligned in vertically north south and horizontal east west direction hence if the outer pixels show the same
48. e electrode This creates the required retarding potential for the 8 electrons of the tritium decay and a background suppression of electrons for instance from cosmic radiation The inner wire electrode system consists of about 200 wire modules Each has a weight of about 20 30kg and these were installed through the large flanges The electrodes are mounted via insulators to the wall 3 1 5 Detector Electrons that pass the analysing plane have to be detected at the FPD Therefore the electrons are accelerated to their initial energy and magnetically guided by two mag nets pinch and detector magnet to the detector The FPD is a semiconductor detector and consists of 148 pixels made of one wafer Each pixel has the same area with 44mm The wafer is placed in the center of the detector magnet with a diameter of 125mm At 19 The FPD has to be able to detect the 18 6keV electrons from the tritium beta decay conversion electrons from Kr 8 to 32keV and electrons from an electron gun Hence the detection efficiency has to be very high in a huge range from low energies to high energies Additionally it is possible to use the post acceleration electrode to accelerate the electrons further up to 30kV The detector is very efficient in the 5keV to 50keV range and low energy electrons can be accelerated to that energy region with the post acceleration electrode As the expected count rate of electrons from the tritium beta decay close to the endpoint
49. e run equals one line scan with as many sub runs as the user wants data points 4 4 ORCA Scripting At the monitor spectrometer the ORCA Script needs to be able to access the IPE Slow Control Object and the Run Control The Script that was used until December 2012 can be found in figure 4 3 The operating principle is described in the following enumeration which refers to the ORCA Script figure 1 function main arg In ORCA Scripting it is possible to define functions These functions may have arguments as in the case of the monitor spectrometer the function main arg has the argument runList As described in section 4 3 the input of this Script object is connected to the output of the Run List and the Script parameters are sent to the Script in an array which is called runList In ORCA Scripting it is absolutely necessary to define at least one function that is called main because ORCA Scripts do not work without this function 2 find arg The find function is necessary to add objects that are in the experimental setup in ORCA The access to this object is shifted into a variable it is called ADEI in this case This variable links to the IPE Slow Control object It is not necessary to look for the name of one object as they can be dragged and dropped into a script which immediately displays its name The name consists of the object name and the counter of objects of this kind this is necessary
50. ed and if the line position does not change the retarding voltage is stable In the following some components of the monitor spectrometer will be explained If not stated differently this section is based on Erh12 24 3 4 Monitor Spectrometer 25 Rb I 5 2 T 86 2 d EC 77 6 83m Kr 1 2 eee T 1 83h conversion Tine electrons E 17824 3 5 eV eo a Pap 2 71 eV AE 32 152 keV lt 7 k32 T amp pane ee S E 30419 6 5 eV ua mis To 1 25 eV 5 p AE 9 4 keV rec E 30472 3 5 eV I 9 2 T 1 19 eV Figure 3 8 Rubidium decay After about 86 days Rb decays to Kr by electron capture As 8 Kr is not stable it decays also one conversion line K 32 will be used at the monitor spectrometer It has an intensity of 17 Zbo11 This figure is taken from Wiel12 3 4 1 Sources At the monitor spectrometer Rb 3 Kr will be used as source material For monitoring the retarding voltage of the main spectrometer at about 18 6kV it is necessary to use a source that emits electrons close to the tritium endpoint Through electron capture Rb decays to amp Kr that can reach its ground state by inter nal conversion or gamma emission One line that originates from the conversion will be used at the monitor spectrometer see figure 3 8 The electrons have an energy of about 17 8keV which means that they have to be accelerated by 800V to leap the 18 6kV retard i
51. ement time at one point and also the time between runs sub runs The reason for this is that the crate sends a histogram always in the same interval thus ORCA Run Control waits after the set measurement time for the next histogram to finish that run because one does not want one histogram at different set values Hence the histogram length has to be synchronized with the Run Length Additionally the histogram length influences the time between runs sub runs because ORCA waits for a histogram to be received before starting the next run sub run Thus it has to be synchronized with the time between runs sub runs also this is even the more important part as the experimenter wants to lose as less time as possible between runs sub runs At the moment the waiting time is set to 13 seconds because it takes one second for the set value to reach the power supply then it has to change the value and the experimenter has to wait for the voltmeters to retrieve the correct values as these have an 34 4 4 ORCA Scripting 35 integration time of about 3 4s For the histogram length four seconds turned out to be a good number After the last histogram of the first run is retrieved the Run List jumps into the next line executes the Script again with the parameters given there After the script finished the Run List waits for the next histogram and starts a new sub run afterwards if the sub run box is check marked or a new run At the monitor spectrometer on
52. ent was 57 58 6 Line Position Stability during KATRIN Measurements done just in the OV to 1000V range and the outcome is very exact The accuracy and precision is very high The size of the circles is chosen larger than the size of the triangles to give a better overview on that figure Overall this measurement shows that the power supply is not usable for measurements of a distinct point on the flank In future this might become possible for KATRIN mea surements But the power supply works fine for line scans as it is shown in this chapter that the voltage is constant for short time intervals The source power supply is ready for both modes as it has a good accuracy and precision In future better measurements of the source power supply become available when the 6 5 digit voltmeter is replaced by a 8 5 digit voltmeter 6 4 2 Time Discrepancy The monitor spectrometer has proven to generate a stable line position within the KATRIN requirements see Erh12 But it is rather difficult to determine a stable line position in a short time The consequences of a reduction of measurement points can be found in also The monitor spectrometer will enable a long term observation of the K 35 divider with respect to a nuclear standard and the possible drift over time Therefore run files need to be created to change voltages of the source power supply The measurement time per sub runs has to be dependent
53. ermi constant M nuclear matrix element 15 16 2 Neutrinos As F Z E and M are independent of the neutrino mass the electron spectrum is only dependent of the neutrino mass within the square root term Additionally there is just the square of the mass within that formula m DD mi 2 46 i For the equation 2 45 it does not matter whether the neutrino is a Dirac or Majorana neutrino While the neutrino mass has little influence on the spectrum in lower energy regions the mass can be derived from the end point energy The spectrum can be seen in figure 2 8 The figure shows spectra with a neutrino mass of 1eV and OeV 1 2 a 100 1 i F Im 80 5 l 3 3 0 8 3 j 60 L r 8 50 6 1 e be 1 40 L f 50 4 i 5 O F 1 o 20 O 1 0 2 f 5 1 O 0 Lomans O 5 10 15 ale oes 3 2 1 O energy E keV E E ev Figure 2 8 Tritium electron spectrum On the left side the complete spectrum can be seen with the energy on the x axis and the count rate on the y axis The right picture shows the energy spectrum at the endpoint The blue line shows the spectrum with a neutrino mass of leV and the red line with a massless neutrino This figure is taken from page 29 Tritium To maximize the fraction of tritium beta decays close to the endpoint x 1 Eo tritium turned out to be very useful as it has an endpoint energy of 18 6keV which is the second lowest endpoint of
54. existing within the nucleus these have a spin 1 2 and obey the exclusion principld that differ to light quanta by not traveling with the speed of light The magnitude of the mass of neutrons has to be same as the ones of electrons at least not higher than 0 01 the proton mass The continuous spectrum becomes perspicuous under the presumption that the 6 decay emits an electron and a neutron in a way that the sum of energy of the neutron and electron is constant Wolfgang Pauli December 1930 loose translation Wolfgang Pauli wissenschaftlicher Briefwechsel mit Bohr Einstein Heisenberg u a scientific correspon dence with Bohr Einstein Heisenberg a o Band II 1930 1939 Radioactive is the name of a group of people 3unknow person Pauli principle 4 2 Neutrinos Within this letter Pauli is stating out two problems On the one hand the wrong statistics of N Li 6 nuclei and on the other hand the continuous spectrum For a two body decay energy and momentum conservation would be violated At that time there were also ideas that the energy conservation for the 6 decay is wrong By introducing a new particle Pauli called neutron the 3 spectrum can be explained and the energy and momentum conservation is working again It was known that the electron does have a spin of 1 2 and the given example of 14 N7 was supposed to have 14 protons and 7 electrons Hence the nitrogen nucleus is a bound state
55. ffset voltage on the sources Run List A 7 This object is used for Run Control at the monitor spectrometer It is able to read csv files these files contain all necessary information about a run at the monitor spectrometer and the run is totally controlled by that object An execution count controls how often the Run List is repeated 31 32 4 Slow Control of KATRIN 8 Catalog A 9 The catolog contains all objects existing in ORCA These can be dragged and dropped to the configuration window There are different connections between objects in ORCA On the one hand we have ob jects that access other objects directly for instance the monitor spectrometer object and the FLT object or the ORCA Script On the other hand we have chains for instance the data chain from Run Control to the Data Readout and from there to the Data Monitor and Storage object The output of one object is always connected to the input of another object like the Run List to an ORCA Script this special data chain contains set values for the voltages for instance There are two more important objects not discussed so far These are the IPE Slow Control object A 8 and the V4 Mini Crate In figure 4 1 these are placed in the Minicrate ADEI Object Pulser container just because it is not necessary to edit them by hand and it improves the clearness of the experimental setup The crate has already been mentioned at the Data Readout see page and it is in
56. findet es relativ schwer und bereits entdeckt sein m te Pauli war nicht v llig berzeugt von seiner Idee Im Jahre 1934 hat Enrico Fermi diese Idee aufgegriffen und den Zerfall durch einen Dreik rperzerfall mit einem freien Teilchen dem Neutrino beschrieben Im Jahre 1956 folgte die experimentelle Best tigung des freien Neutrinos Insgesamt gibt es drei Genera tion von Neutrinos das Elektron Myon sowie das Tau Neutrino Im Standardmodell der Teilchenphysik werden Neutrinos als masselos angenommen allerdings haben Neu trinooszillationsexperimente gezeigt dass Neutrinos von einer Generation in eine andere bergehen k nnen Dies ist einhergehend mit der Annahme dass Neutrinos nicht masselos sein k nnen Demzufolge musste das Standardmodell erweitert werden Durch die Neu trinoflavouroszillationen ist auch die Leptonenzahl innerhalb einer Teilchenfamilie verletzt und das Standardmodell musste dementsprechend angepasst werden Da es nicht m glich ist aus Oszillationsexperimenten auf die absolute Masse der Neu trinos zu schlie en sind weitere Experimente notwendig Man unterscheidet zwischen modellabh ngigen Neutrinoloser Doppelbetazerfall und weniger modellabh ngigen Experimenten Das KATRIN Experiment KArlsruhe TRItium Neutrino wird aus dem Tritiumbetazerfall auf die Neutrinomasse r ckschlie en und setzt damit lediglich Fermis wohletabliertes Modell der schwachen Wechselwirkung voraus Hierzu wird das Elek tr
57. fit program there are two main fitting functions e Doniach Sunjic This function is preset in the fit program This function looks like a normal bell shape but has an asymmetrical part in the lower energy region This asymmetry is described by the a parameter that is not the same parameter as in the y function e Voigt This function is a convolution of a Lorentzian and a Gaussian function For the spectra of implanted sources a single Voigt function is not sufficient and a doublet of Voigt function has to be used To switch between those functions the fit cpp needs to be edited and the program needs to be recompiled 5 2 3 Outlook As createfilterspec is able to run autonomous it should be possible to integrate it into the KATRIN DataProcessor This makes it possible to download the ROOT files directly from the server which is faster for the user as the raw data is already analysed but also the ROOT files are much smaller as they consist of much less histograms But the user has still to be able to analyse the data on its own thus the createfilterspec on the end user machine needs to be able to perform the same work but with an extended program to offer an option to download the analysed data immediately There are also thoughts to combine the createfilterspec and the MoS_fitter into one pro gram package once a standard model for the line shape is established 47 5 Data Analyis Software 48 Pulserspectrum 158542
58. g plane a field of 3G The electrons are guided through this magnetic field and perform a cyclotron motion The proportions of the spectrometer is very huge hence although the magnetic field drops many magnitudes the variation of the magnetic field over one cyclotron turn is small Full Width Half Maximum 21 22 3 The KATRIN Experiment Event Rate Rate Hz 3 2 5 2 1 5 1 0 5 0 Figure 3 5 Measurement of an americium source with the FPD This figure shows the rate on each pixel with an americium source that is very homogeneous There are also two broken pixels these are probably shorted on the wafer Thus the magnetic moment u which is given by Ei t 3 1 cons 3 1 is constant This leads to a transformation of the perpendicular energy the cyclotron energy into longitudinal energy Hence in the analysing plane almost all the energy is within the longitudinal part If this energy is sufficient to pass the electrostatic potential these are re accelerated and collimated onto the detector The sharpness AF of this integrating high energy filter can be derived from equation 3 1 Ba Braz AE Eo 3 2 See figure 3 6 for naming convention of the variables This means that the sharpness is dependent on the ratio of B4 Bmaz only and an ideal integrating high energy filter with maximum sharpness would require Ba 0 This cannot be realised in an experiment The ideal filter looks like
59. g them sequentially but downwards The red squares show the trend of the line position by using the central histogram of each sub run The following run times are calculated by using the histogram before and after the central histograms until all histograms are used at 62 seconds The first measurement points show a large error on the line positions The run length of 2s causes an error above 100meV for all three measurement points additionally the line position between the central histogram and the first histogram are over 100meV apart This shows that one histogram of a length of two seconds is not enough but it is an acceptable appraisal as the line position with its errors contain the correct line position After a measurement time of eight seconds the error on the line position drops below 5l 52 6 Line Position Stability during KATRIN Measurements o central 2 5 first O a 24 95 last Q k 4 9 4 85 i HHHH A 4 75 A 0 10 20 30 40 50 60 time s Figure 6 3 The dependency of the measurement time on the line position On the y axis the relative line position in electron volts can be seen On the x axis the measurement time in seconds is shown The blue triangles show the progression of the line position beginning with the first histogram the red squares the progression beginning with the central histogram of one sub run and the black circles beginning with the last histogram The his
60. gnetic neutrinos component component Figure 2 2 Air shower caused by cosmic radiation On the left side the described neutrinos can be seen This figure is taken from HRRO03 2 2 3 Supernovae Neutrinos There are two types of supernovae type I and II Supernovae with hydrogen lines in their spectrum are called type II with none type I These supernovae types can be subdivided even further In this section only a look at type II is taken as plenty of neutrinos do arise from that type After a star burned all the internal hydrogen the pressure of radiation is not sufficient to counteract the gravitation and the star contracts Caused by this contraction the internal temperature does rise again and the star can burn helium what removes the star from the main sequence as it becomes a red giant After a short time this helium is burned and the produced elements like nitrogen oxygen and carbon are burnt after further contraction also When the star begins to burn carbon the energy losses through neutrinos become dominant If the mass of such a star is at least eight times the mass of the sun it is able to generate enough pressure and high temperatures to burn everything to iron After everything is burned to iron the star does not have any fuel left Finally if the mass of the iron core is higher than the Chandrasekhar masq the star becomes instable and collapses to a neutron star The collaps is caused by photodesintegration and electron
61. handicap As a conclusion it can be said that the measurement time multiplied with the activity should not be lower than 30 s 309 43 kBq 9300 kBas for an error on the line position lt 25 mV For an error lt 20 mV this value may not be lower than 16100 kBas A plot of the error on the line position over time can be seen in figure 6 4 6 3 Temperature Dependencies During measurements with varying source potentials the voltage on the vessel is constant and it becomes possible to take a look at the behaviour of the power supply at constant voltages For that power supply oscillations became visible see 16 5 After further inves tigation it turned out that further meters show the same behaviour and it is caused by temperature fluctuations In this section a look at these fluctuations is taken and their consequences for the measurement 6 3 1 Influence on the High Voltage System In figure 6 5 oscillations of the high voltage at the monitor spectrometer can be seen The voltage is set to constant 18000V within the power supply This voltage is applied to the vessel These oscillations have a period of about 1h for the K 35 and JR divider volt meter and show the same behaviour Both are in separate buildings The JR divider and voltmeter is in the monitor spectrometer building and the K 35 in the main spectrometer building Hence the power supply has to be responsible for the voltage oscillation It turned out that the oscillati
62. histogram and just this histogram is saved This has the huge advantage that the output files are really small and the analysis is really fast Thus this script had to be removed from the experimental setup and additionally the option Ship Sum on the FLT card had to be deactivated as the last summed histogram is not necessary and consists of no useful information for analysig The histogram length has been set to two seconds and the size of such a histogram as a Raw ORCA file is about 65kB average This means that saving all histograms requires about 114MB of hard disk space per hour In comparison to runs without sub runs and a run time of 30s for one measurement point and the using of the Filterscript requires about 8MB only Hence the output file is about 14 times larger than without sub runs As a consequence the output file size has been de creased by about a factor of 2 by doubling the histogram length Increasing the histogram length further might cause problems see 4 3 There is no final solution to that problem yet It has not been possible to realise a Fil tescript that is capable to handle sub runs The only solution might be a hard coded solution that would have to be realised by Mark Howe and Till Bergmann At the mo ment the monitor spectrometer is using sub runs and except the size of the output files it works fine In the very beginning of using sub runs there has also been a problem that the Run List in OR
63. hitrate the central pixel is aligned accordingly to the flux tube To change the position of the detector it is possible to move it in x y and z direction This setup is very different to the Mainz setup The Mainz detector had five circular elements each with a size of Icm The new setup eases the replacement of broken detectors 248270 9 nT total intensity February 2013 Hell3 27 4 Slow Control of KATRIN The KATRIN Experiment is going to use ORCA Object oriented Real time Control and Acquisition for data acquisition and slow control The advantage of ORCA is that it uses a client server model and separates the hardware controlling computers from the user interface computers Therefore we have a system that is taking and processing the data while there can be multiple remote clients to control them Kat05 Since 2011 data taking has been working fine at the monitor spectrometer using ORCA But the slow control was still done by a program written in LabVIEW by Michael Schupp Sch11 It was directly connected to all necessary devices and so did not fulfill the KATRIN requirements to be an independent remote controllable system One main task of this thesis is to switch to an ORCA based slow control and to automatise monitor spectrometer measurements which is described in this chapter 4 1 Introduction to ORCA ORCA evolved from SHaRC SNO hardware acquisition and real time control which was developed by John Wilke
64. in until a retarding potential of 18600V was reached These scans can be seen in figure 6 1 Additionally a scan of the L 32 con version line was done These scans were carried out with identical source voltages and the retarding potential was set from 30650V to 31250V These scans can be seen in figure 6 2 For both scans the Pt30 5 source was used as it was the source with the highest activity during these measurements 49 50 6 Line Position Stability during KATRIN Measurements 492 gt relative line position e gt p gt 00 00 O o 4 84 4 82 4 8 4 78 no offset voltage 4 76 offset voltage applied 4 74 0 20 40 60 80 100 120 140 160 180 200 relative time h Figure 6 1 The position of K 32 conversion line of source Pt30 5 On the y axis the relative line position in electron volts can be seen and on the x axis the relative time in hours The blue circles are measurements with varying source potential and the red squares measurements without gt 25 19 no offset voltage gi _ offset voltage applied a _ N relative line position or ep 0 20 40 60 80 100 120 140 160 relative time h Figure 6 2 The position of L 32 conversion line of source Pt30 5 On the y axis the relative line position in electron volts can be seen and on the x axis the relative time in hours The blue circles are measurements with varying source potential
65. ips7A e p E lt 0 42MeV pp 2 13 pte p gt H tve E 1 44MeV pep 2 14 3Het p r He ue et E lt 18 77MeV hep 2 15 Bete gt Li rve E 0 862M eV 0 384M eV ppII 2 16 8B Bete v Ep lt 14 06MeV ppIII 2 17 The processes without neutrino production are omitted These reactions result into mo noenergetic neutrinos pep ppII and neutrinos with continuous energy distribution pep 2 3 Neutrino Oscillations 9 hep and ppIII Within the sun the pp process is dominant Neutrinos from the CNO cycle result from the following reactions By BO 4 et tn Ey lt 1 2MeV 2 18 BO JUN petim E lt 1 73MeV 2 19 These neutrinos are not monoenergetic and for the sun these processes can be neglected as the CNO cycle is responsible for just 1 6 of the overall energy production An overview of the solar neutrinos and their fluxes can be seen in figure 2 3 see KKZ97 pages 348 355 2 2 5 Reactor Neutrinos Reactor neutrinos originate from the decay of neutron rich nuclei In the 8 decay they emit anti neutrinos The neutron rich nuclei are the result of the fission of 5U and 39 P for instance The average emitted number of anti neutrinos for 2 U are 6 1 neutrinos and 5 6 neutrinos for 78 P Hence a reactor of 1MW causes approximately 2 10 anti neu trinos These neutrinos are perfect for neutrino oscillation measurements Experiments considering neutrino oscillations will be di
66. is the mass m in electron volts can be seen Up to about 0 leV the mass eigenstates are discrete and hierarchical with m3 gt ma gt m Afterwards the mass eigenstates are quasi degenerated mass eigenstates This figure is taken from Kat05 page 14 Q lt 0 14 3v tritium experiments mm lt 0 6 eV 3v 0 01 Super Kamiokande zm gt 0 05 eV tv 9 001 i gt 0 Q gt 0 001 1v Q Figure 2 6 Energy Density within the universe On the left side the contribution of the neutrinos in dependence of their mass can be seen and on the right side the contribution of stars gas baryons dark matter and the dark energy This figure is taken from Kat05 page 16 13 14 2 Neutrinos Z Figure 2 7 Mass parabola On the x axis the proton count can be seen and on the y axis the energy or mass This figure describes the course of double beta decay 2 4 1 Double 6 Decay The double beta decay describes the decay of two neutrons at the same time into an instable core In comparison to the usual beta decay the double beta decay is a rare process Tow cases can be distinguished e Normal Double Decay 2v A Z gt A Z 2 2e 2v 2 39 e Neutrinoless Double 8 Decay 0v A DSA 2 40 For the first case the lepton count is correct and does not change AL 0 the neu trinoless decay does not have a constant lepton count AL 2 In an experiment it is easy to differentiate be
67. ished and ships it then This option does exist on the FLT card also and was deployed when not using sub runs This gives small but many output files Unfortunately it does not work with sub runs yet see 4 5 1 e Accumulate If this option is enabled the histograms are not cleared at the end of a run Data Storage A 4 This object determines where the data are saved There are three different types of data the run data the log files and the config files Each file destination can be set in that object Additionally the directory structure and a run file prefix can be chosen Monitor Spectrometer A 5 The monitor spectrometer object consists of a graphical interface that shows an image of the detector at the monitor spectrometer If every detector is connected to the correct FLT card channel this object is capable to show the rates on each channel to the user in real time There are equivalent ORCA objects for the FPD Focal Plane Detector Additionally the user can start and stop a run in that object as well as set the run time and chose between offline and normal runs ORCA Script A 6 The ORCAScript is a very powerful object It can access objects and perform the same operations with these objects as a standard user and even more Scripts are very useful for the automatisation of measurements These scripts are used at the monitor spectrometer to set and change values for instance the voltage on the vessel or the o
68. keVa lueVesse l 5000 5 ADEI valueForChan F lukeChanvessel source Voltage FlukeValue Vessel Voltage FlukeValueVessel ie1 abs Voltage FlukeValue abs Voltagevessel FlukeValuevessel while abs Voltage F lukeValue gt 8 2 abs Voltagevessel FlukeValueVessel gt 2 Outputs Name Value hex Name Value hex E y 4 3 The ORCA Slow Control Script at the Monitor Spectrom eter This Script is able to access the Run Control object and the IPE Slow Control object The Script gets its parameters from the Run List In the highlighted lines the following is written down 1 function main runList 2 ADEI find ORIpeSlowControlModel 1 3 Volt ageChanVessel ADEI findChanOfControl http 192 168 110 67 adei path monitorspec monitorspec 3 0 4 ADEI queueControlSetpointFor Chan VoltageChanVessel value VoltageVessel 5 ADEI sendSetpointRe questQueue For a detailed description see page 35 37 38 4 Slow Control of KATRIN sub runs first runs with sub runs were recorded To make analysis easy the idea has been that one run equals one line scan and each measurement point one sub run The first runs have been filled with just one histogram the reason has been a Filterscript written by Mark Howe that has prevented histograms to be written to the output files except the last one This makes sense for normal runs without sub runs because all histograms are just summed up to one
69. ks in our histograms is lower a higher standard de viation leads to less found peaks in the background Additionally a threshold called Peak Ratio in the parameter file is necessary This threshold defines the ratio of the y value of the low peak divided by the high peak If this ratio is below the threshold the small peak is neglected This value is set to 0 01 by default as it is reasonable for most line scans sometimes it is necessary to be lowered which is done by the program automatically If the program found the correct amount of peaks a check of their positions and sigma is done The sigma is calculated with a gaussian fit of these peaks Their boundaries are derived from the x value the peak search found previously and three times a standard sigma that has to entered in the parameter file It turned out that 8 is a reasonable number for the standard sigma These boundaries are used for gaussian fit that returns the real fitted sigma Createfilterspec checks whether the fitted sigma and the positions of the peaks are correct and starts the integration If the check fails it either stops because it cannot find the correct peaks or it lowers the peak ratio automatically and restarts the peak search The integration is done in a three sigma range therefore the fitted sigma is added three times towards lower ADC values and towards higher ADC values from the maximum All counts within this range are summed and represent the peak
70. librations and sensor addresses on ADEI It serves also as a slow control cache The slow control data that was downloaded from ADEI once is stored there and enables a faster access to this data The database can be edited and new sensors can be added with the database webbrowser Besides the access to the KATRIN Dataprocessor with the web browser it is possible to access it via Kasper which contains KaLi KaLi is able to download run and slow control data available on the IPE server and it is able to write to the calibration database also 5 2 The Monitor Spectrometer Analysis Software In the course of this work the analysis of monitor spectrometer data was improved A new program for raw data analysis incorporating new features had to be written and the Doniach Sunjic function was introduced alongside with a new fit program In the following a detailed description of raw data analysis and an introduction to the fit program is given http orca physics unc edu markhowe Subsystems ORCARoot html 3http root cern ch 42 5 2 The Monitor Spectrometer Analysis Software 43 5 2 1 Raw Data Analysis Responsible for the raw data analysis of the Monitor Spectromter data is a program called createfilterspec originally written by Stefan Groh and Moritz Erhard It was able to download runs and access slow control with KaLi data to generate the filterspectra from that data In the following section a rewritten version of this prog
71. lled MoS_fitter based on a fit program from Mainz that was rewritten by Martin Slezak and is able to handle the output files created by the createfilterspec program and to fit the output data As the measurement process at the monitor spectrometer is automatised with ORCA Scripts the same is wanted for its analysis A large amount of this thesis has been to rewrite the createfilterspec program and make it as user independent as possible The idea is that the raw data analysis of the monitor spectrometer is done on the server side in future and not on the local user machine This makes analysis faster and more fail safe In this chapter an introduction to the server structure and Kali is given and the data analysis is described in details 5 1 Introduction to the Server Structure To enable the user to analyse data the access to slow control and run data is required The data flow is shown in figure 5 1 This figure is a direct continuation of the server structure of slow control in figure The slow control data from ZEUS stored in the MSSQL database see are replicated from the KATRIN network to a MSSQL database on a server located at the IPE With these data also the PCS7 Process Control System data is stored in that MSSQL database The database is read by ADEI and enables access to the slow control including PCS7 data A direct link to ADEI is possible via web browser and the KATRIN DataProcessor The data transfer between ADEI and the
72. ltage on the vessel at the monitor spectrometer should be more stable as the voltage is identical to the main spectrometer voltages and the power supplies in the main spectrometer hall are placed in much more stable temperature con ditions These measurements were done during noon but identical curves during night measurements can be seen Probably these fluctuations are caused by the air condition ing heating system at the monitor spectrometer building Unfortunately these cannot be read out directly As the power supplies as well as the voltmeters are sensitive to temperature changes the gate to the east should not be used but the small door to the west especially during winter and summer season In future run control should be done from the control room 6 3 2 General influence on the Monitor Spectrometer The temperature does not just have an influence on the high voltage system fluctuations can also be seen on different sensors For instance the pressure sensors show the same behaviour see 6 8 Of course these temperature fluctuations do not influence the pressure directly but they do influence the sensors Again the conclusion has to be to keep the temperature as constant as possible by influencing the temperature as little as possible from outside 59 56 6 Line Position Stability during KATRIN Measurements V 9 17998 92 Volta 17998 9 17998 88 17998 86 17998 84 17998 82 17998 8 17998 78
73. luxes are explained in the following sec tions This figure is taken from For13 out decouples The decoupled neutrons decay And the decoupled neutrinos are the pri mordial neutrinos with a temperature of about 1 95K at present The primordial neutrino density is about 336 cm see KKZ97 pages 148 149 2 2 2 Atmospherical Neutrinos When protons from the cosmic radiation hit particles in the upper layers of the atmosphere of the earth for instance a nitrogen nucleus p N gt r K 2 6 pions and kaons can originate from it These can result in a cascade of particles and if they dot not have sufficient energy possibly lost through interactions they decay n KE u v Du These muons are not stable also and decay UF gt e ef BaF yl Op This results into a ratio of _ aa _o Ve t Ve 2 7 2 8 2 9 if all muons disintegrate In case they have a high energy the ratio shifts towards the electron neutrinos A particle shower can be seen in figure 238 246 2 2 see KKZ97 pages 235 2 2 Neutrino Sources 7 Primary Particle Y nuclear interaction K eG with air molecule DE 0 0 T A n lt K K on Sai h u Y Y hadronic 4 y y v V cascade ee amp e ee Cherenkov fluorescence radiation tE T ae u p n T K e yeyye y e nuclear fragments muonic component hadronic electroma
74. ly a cross check with the pulser time is included The counts of the pulser on the channel 0 are summed and the counts divided by the frequency result in the run time If these two run time values differ too much an error is put to console and the program uses the run time derived from the histograms It is also possible to use the pulser run time this option can be found in the settings of the parameter file As the settings on the FLT are fixed the Run Time may be derived by the ORCA time stamps too The Slow Control Data The Slow Control Data is obtained through KaLi Therefore the KATRIN Number as well as its time stamps for the desired channel are necessary The KATRIN Numbers for the voltages are not hard coded and can be edited in the parameter file The time stamps are derived from the header files of the runs or sub runs Then it is possible to download the mean values as well as the standard deviation of each channel via KaLi functions After the voltages for the vessel and the source are derived the program automatically subtracts the source voltage from the vessel voltage to get the filtervoltage If the voltage applied to the source is below 5V it is expected that the source is not connected to the source power supply and the source voltage is neglected Createfilterspec is also able to download the source position as it is necessary for the fit program This works the same way as in the case of the voltage data but the KATRIN
75. m The current version can be found in the appendix section A 4 At the monitor spectrometer a pulser is connected to the zeroth channel of the FLT card and also to the central detector segment channel 4 This enables dead time correction but also the possibility to calculate the run time with it In the parameter file the user can specify whether a pulser is connected and its frequency and also whether the run time should be derived from the pulser Ifthe user wants to analyse many runs at the same time it is possible to deactivate the time consuming plotting of the data as well as the read out of source data For some analysis it might also be interesting to take a look at data of a different detector segment as well as to save the output data into a txt file and not just a ROOT output file These settings are available in the parameter file Additionally it is possible to influence the integration with a specified standard deviation sigma and a ratio of peaks these will be described in the next section Deriving peak counts from the Energy Histogram The input of KaLi are ROOT files containing the run data KaLi downloads these files and access their data As the monitor spectrometer is measuring in histogram mode the ROOT file consists of histograms For each run sub run these histograms need to be summed and put into one histogram Histograms between sub runs need to be neglected The summed histogram is the so called energy histog
76. mber as well as run number The run number is just saved as an integer value hence just the run numbers and not the sub runs numbers are saved This kind of ORCA Scripting is confusing and hard to use for future experimenters Addi tionally the DAQ machine at the detector will probably not use the Run List but control the measurements with ORCA Scripts only Hence every experimenter has to write his own scripts which is made easier by an ORCA Script library package It can be found on the Git Repository and all necessary functions will be included there For the monitor spectrometer all required functions are already included and working fine The addresses of sensors and control channels are already included if one channel does not exist in the IPE Slow Control object it will be created automatically These libraries can be included via the import function at the top of an ORCA Script A list of functions can be found in the included documentation of these libraries A de scription of functions for the monitor spectrometer and the script used right now can be found in the Appendix 4 5 Problems and Solutions Accompanied by the switch to ORCA run control sub runs became available Therefore first test measurements with sub runs were done to write raw data analysis software that is capable to handle sub runs see 5 2 1 When a first look into the data was taken it turned out that the error on the voltage w
77. nControl libs SDS_MonitorSpectrometer 1lib function main runList find the Run Control Object in your Experiment to access data of that object runControl find ORRunModel 1 read and save all values from the RunList this is not necessary but done for easier understanding lineNumber runList 0 sourceVoltage runList 1 vesselVoltage runList 2 waitTime runList 3 the runNumber is received from the runControl Object that is why we needed to include it runNumber runControl getCurrentRunNumber check whether the Voltages are not above a certain value you can edit these values but check the Range of the Voltmeters before if vesselVoltage gt 33500 print The VesselVoltage vesselVoltage is too high print Returning without changing the Voltages return if sourceVoltage gt 850 print The SourceVoltage sourceVoltage is too high print Returning without changing the Voltages return to be on the safe side we do not send every value to ADEI control on its own but in a queue these queues are created with pre defined functions queueCurrentLineNumber lineNumber queueVoltageSource_V sourceVoltage queueVoltageVessel_V vesselVoltage queueCurrentRunNumber runNumber finally the queue is sent sendADEIQueue now the script is waiting for the setvalues to be changed sleep waitTime 77 78 Appendix A 4 Parame
78. ne by shifting the set value of the source or vessel power supply This shifting can be done from up down or just random values close to the actual line position The advantage of up and down scans is a more stable voltage as the shifts are usually small There are two possibilities to decrease the time of one line scan First the count of measurement points can be decreased This was already done in the diploma thesis of Michael Schupp and Moritz Erhard Erh12 Both diploma thesis also treated the dependence of the measurement time on the line position but with the switch to sub runs it became possible to look at on single run and split it into its single histograms and check the dependence of the measurement time Therefore a closer look at run 150662 is taken This run consists of 44 sub runs with a run time of 62 or 64 seconds each The histogram length is set to two seconds In figure 6 3 the K 32 line position is plotted at different run lengths On the x axis the run length can be seen the run time needs to be a multiple of the histogram length 2s On the y axis the relative line position of the K 32 conversion line can be seen Within this figure are three different strands The blue triangle shows the behaviour of the line position in standard analysis the first histogram of one run is taken and the following are processed sequentially The black circles show the line position beginning with the last histogram of one sub runs and processin
79. ng voltage In comparison to the retarding voltage the accelerating voltage with about 800V can be measured very precisely with a 8 5 digit voltmeter If this is not sufficient a high voltage divider can be used The rubidium is ion implanted in a solid commonly platinum foils This can be in serted into the source chamber on the source holder It is possible to insert four source holder into the source chamber at the same time The entire source is placed on a cross table that enables the experimenter to move the source in z direction that means in the direction of the beamline to different magnetic fields as well as to move it into the x and y direction to position each of the four sources in the center of the flux tube Besides it is possible to apply a voltage to each source separately so that the energy of the electrons can be matched to the potential on the main spectrometer During the course of this thesis the source voltage combined with the retarding voltage was tested and the results can be found in chapter 3 4 2 Spectrometer The spectrometer tank has a length of three meters and a diameter of one meter The working principle is identical to the main spectrometer The difference is that there is no potential on the outer wall but there are wire electrodes and solid electrodes see figure 3 9 The solid electrodes are in between the outer wall and the wire electrodes These are 25 26 3 The KATRIN E
80. o the compact Field Point The right side shows the data flow from the Webbrowser to the compact Field Point The current and set values are saved in a MSSQL database able to communicate with all necessary hardware devices ORCA and the IPE Institut f r Prozessdatenverarbeitung und Elektronik Database The program was able to read Excel files which were used to set all parameters These parameters are the set values of the voltage the waiting time between runs while the voltage is set and the measure ment time As data from the crate is recorded by ORCA the LabVIEW program had to be able to control ORCA and set ORCA parameters remotely The connection to the hardware was realised through direct connections to the devices for instance a serial line to the high voltage power supply from the Windows machine to the device or via Ethernet to the GPIB converters connected to the voltmeters and to the MAC Mini running ORCA Because there were constantly measurements at the monitor spectrometer the implemen tation of Run Control with ORCA had to be smooth and user friendly as well as instantly during measurement pauses The only problem was the high voltage power supply which is absolutely necessary for measurements at the monitor spectrometer and had to be in tegrated into the Field Point still The final integration caused some days of no mea surements The overall idea was to keep the measurement control simple and alike the mea
81. odel independent experiment is the KArlsruhe TRItium Neutrino Ex periment KATRIN that can measure the neutrino mass to a sensitivity of 0 2eV c 90 C L from the 8 decay of tritium This is a factor of ten better than previous experiments at Mainz and Troitsk To realise such a high sensitivity a spectrometer based on the MAC E Filter principle is used It is very important to guarantee a stable filtering voltage on this spectrometer therefore high voltage divider with the worlds best precision are used as well as the monitor spectrometer that enables voltage monitoring on a nuclear basis This thesis will introduce the neutrinos chapter 2 to the reader and explain the KA TRIN experiment in more detail chapter B Afterwards the Run Control of the monitor spectrometer is explained which is the pre test of measurement control for the whole KA TRIN experiment chapter 4 The recorded data needs to be analysed in the course of this thesis a raw data analysis program has been rewritten what will be explained in 1 An excerpt of his letter stating out a third involved particle called neutron can be found on page p 2 1 Introduction chapter 5 Afterwards a look at the line position stability under different prerequisites is done in chapter 6 2 Neutrinos Liebe Radioaktive Damen und Herren Wie der berbringer dieser Zeilen den ich huldvollst anzuh ren bitte Ihnen des n heren auseinandersetzen wi
82. of these particles with half integer spin But it was found out that the nitrogen follows the Bose Einstein statistics Thus by implementing a neutron into the nucleus with a spin of 1 2 this problem is solved also This section is partly taken from Bil12 Pauli himself was very uncertain with his own theory He assumed that the neutron has to have a mass as part of the nuclei and it may not be above 0 01 of the proton mass In the complete letter he states that he does not want to publish his idea because he is sure that this particle must have been found already Ironically the neutron as we know it today was found in 1932 by James Chadwick Cha32 It has the mass of about the proton has no charge and spin 1 2 But it is not the particle Pauli was talking of One problem that Pauli described in his letter was solved by the theory that the nucleus consists of a bound state of neutrons and protons But the problem of the 3 spectrum still remained Enrico Fermi picked up the problem and developed a theory with a small spin 1 2 neutron the neutrino in 1934 Fer34 The 8 decay that Pauli describes can be explained with the following formula aX gt a Y te 7 2 1 It took additional 22 years until an experimental verification of neutrinos at the Savannah river nuclear power plant in the USA in 1956 This work verified the Hanford experiment that might have proven the free neutrino in 1953 already It was using the inver
83. ometer xy CRU a a KE Status Log Alarm Master Catalog HWWizard Preferences CommandCenter Print Customize Detector Details HW Map Selected Segment Info lt nothing selected gt Run Control Run 0 gt Status Stopped C Stop After 3600 secs _ Repeat Normal Offline Config Checks _ C Skip HW Checks 7 Hardware Configuration 7 Card Check Capture Current State O Log Rates Clear Se FF C Display Names Total Rates f 500 0 0 00 Newest 12 22 09 58 27 Ei Figure A 5 The Monitor Spectromter object This object shows an image of the detector and if connected to the FLT card also the hit rates on each detector channel in the bottom the total rates over time are plotted and the user can access features of Run Control from within this object 72 A Orca 73 ee _u000 BB 09 bare C Break Chain O Start With ORCA File OC Run Hinport ORCARunControl 1ibs S05_NonitarSpectroneter 11b unction mainQrunList find the Run Control Object in your Experiment to access data of that object runControl f ind ORRunMode 1 read and save all values from the Runlist this is not necessary but done for easier understanding LineNunber runl ist sourceVoltage runl ist 1 vesse Voltage runl ist 2 waitTime runl ist 3 the runNumber is received from the runControl Object that is why we needed to include it runNunber runCon
84. on the activity of the source see page 51 These run files need to be adapted after a while to the weaker activities Within this chapter it is shown that the measurement principle does work and gives expected results In future further measurements have to be done by varying the source potential and by using a more precise voltmeter Additionally for KATRIN measurements slow control has to become more reliable and faster to make short measurement times and high activity sources much more efficient 58 7 Conclusion Since the first idea of neutrinos in 1930 over 80 years have passed In these years the neu trino research progressed and occasionally performed giant leaps the discovery of three neutrino generations and neutrino oscillations which comes along with massive neutrinos Neutrino oscillation experiments cannot measure the absolute mass which makes different experiments necessary Until now it was possible to measure an upper limit of neutrinos m v lt 2 05eV 95 C L The KATRIN Experiment KArlsruhe TRItium Neutrino is the successor experiment to Mainz and Troitsk From the electron beta decay spectrum the mass of the electron anti neutrino can be determined KATRIN will improve the sen sitivity by a factor of ten and set an upper limit of the electron anti neutrino mass of 0 2eV 90 C L if the absolute mass cannot be determined KATRIN is planned to have a measurement cycle of five years therefore it is necessary to h
85. onenspektrum des Tritiumbetazerfalls am Endpunkt untersucht Die Sensitivit t wird 0 2eV 90 C L betragen also eine Gr enordnung besser als die direkten Vorg ngerex perimente in Mainz und Troitsk Dazu besteht der 70m lange experimentelle Aufbau aus einer fensterlosen gasf rmigen Tritiumquelle die durch den 6 Zerfall freiwerdenden Elek tronen werden durch die Transportstrecke geleitet und vom Tritium getrennt Der Elek tronenfluss wird im Vorspektrometer um einen Faktor 10 verringert und die verbliebenen Elektronen werden im Hauptspektrometer weiter gefiltert Somit k nnen nur Elektronen mit einer Energie von 18 6keV den Filter passieren Diese Elektronen werden am Fokalebe nendetektor registriert Um diese hohe Sensitivit t zu erreichen ist eine sehr genaue Filterspannungsmessung vi 0 Zusammenfassung am Hauptspektromer n tig Hierzu gibt es zwei Hochspannungsteiler die ein direktes Auslesen der Spannung ber kommerziell erh ltiliche Voltmeter erm glichen Desweit eren wurde das Monitorspektrometer installiert welches eine Hochspannungs berwachung basierend auf einem nuklearen Standard erm glicht Im Rahmen dieser Arbeit wurde die Messsteuerung am Monitorspektrometer komplett auf ORCA dem Datenaufnahme und Kontrollsystem umgestellt sowie ein neues Programm zur Rohdatenanalyse geschrieben Desweiteren wurde die Linienstabilit t unter verschiedenen Laufzeiten und u eren Ein fl ssen untersucht e Messbetriebsste
86. ons are caused by the temperature In figure 6 7 the same behaviour as for the voltage can be seen on the temperature The used time interval for this plot is exactly the same as for the voltage The difference in voltage from tale to peak is 100mV The question is the influence on the line position A plot of 100s intervals for the same time range can be seen in 6 6 The voltage within these intervals is relatively constant and the maximum error on the flank is 12mV Usually even shorter measurement times than 100s per measurement point are taken which results into shorter time intervals with smaller errors on the voltage 54 6 3 Temperature Dependencies 55 S x F k35 Divider D YK HOOK Ao em 6 x ORC OK x oe S 17999 2 JR Divider az 17998 95 17998 9 l 17998 85 17998 8 0 1000 2000 3000 4000 5000 6000 7000 time s Figure 6 5 Voltage oscillation of the high voltage power supplies at constant set value On the y axis the voltage can be seen During this measurement the voltage was set to 18000V at the power supply On the x axis is the time in seconds The blue crosses are the measurement points of the K 35 divider and the red rotated crosses show the voltage at the JR divider Usually the offset between the JR and K 35 divider is greater the y values of the JR divider were reduced by 1V manually to show that both voltmeter have the same behaviour For KATRIN measurements the vo
87. precision measurement close to the tritium endpoint of electrons is performed Finally the electrons that passed the filter are registered at the FPD In this section an introduction to the components and the MAC E Filter is given 3 1 1 The Tritium Source The electrons that KATRIN wants to detect stem from the d decay of Tritium Therefore the KATRIN experiments can benefit from the Tritium Laboratory Karlsruhe TLK that is the only licensed scientific laboratory to handle the required amount of tritium They have a license of 40g tritium this equals 1 5 10 Bq The TLK has a closed tritium cycle also and their expertise may not be underrated Therefore the WGTS was developed see figure 3 2 it offers highest luminosity and com pared to e g solid sources small systematic uncertainties The WGTS is a 10m long cylindrical tube with a diameter of 90mm The tritium is injected through 250 capillaries with a diameter of 2mm in the middle of the tube It has a temperature of 27K and is of high isotopic purity gt 95 The WGTS has a fixed column density reference value of pd 5 1017 molecules The injected tritium reaches the outer regions of the WGTS through diffusion This leads to a non linear decrease of tritium density towards the outer regions The largest uncertainty of the WGTS is the column density it has to be known to a precision of 0 1 This can be adjusted by the gas injection pressure and the source tube temperature
88. r 3 1 5 Detector 3 2 MAC F Filter 3 3 High Voltage Monitoring 3 4 Monitor Spectrometer 3 4 1 Sources 3 4 2 Spectrometer 3 4 3 Solenoids 2 2 2 Atmospherical Neutrinos 2 22 22 2 moon nn 3 4 4 Low Field Correction System 2 2 2 2 Con nn 3 4 6 Detector 4 Slow Control of KATRIN 4 1 Introduction to ORCA 4 2 Overview of the Server System 3 4 5 Earth Magnetic Field Compensation System 17 17 18 18 19 19 20 21 23 24 25 25 26 26 26 27 Contents 4 3 Run Control of the Monitor Spectrometer 24 32 4 4 ORCA Scripting 2 22 Coon nn 35 4 5 Problems and Solutions 2 2 2 22m a 36 4 5 1 SubRuns 2 2 2 Coon 36 4 5 2 Eimestamps s s e 2 2 es a e eb sen nr sa innen 38 4 5 3 Slow Control i e res eaey s si gab Koa ai aaa e ua AO ea 38 5 Data Analyis Software 41 5 1 Introduction to the Server Structure oaa a a a a 41 5 2 The Monitor Spectrometer Analysis Software 2 2 2222 42 5 2 1 Raw Data Analysis ae a ee els ek ee rn 43 The Parameter
89. ram It shows the counts of one run sub run on the y axis and the ADC channel on the x axis Usually this histogram has two distinct peaks at detector 4 the first one shows the counts on the detector by electrons at lower ADC values and the second one at higher ADC values is caused by https nuserv uni muenster de cgit cgit cgi createfilterspec git https nuserv uni muenster de cgit cgit cgi Kasper git Shttp www boost org 43 44 5 Data Analyis Software X x x 1 P 2 x Figure 5 2 The peak search of TSpectrum This picture shows how TSpectrum evaluates a peak If a peak is found with x coordinate xp the sigma entered in the constructor of TSpectrum is used to derive new x coordinates 21 2 Lp 3 o0 The y values of x and x2 are averaged to gain the peak height h Yp y y2 2 This sigma is hard coded in createfilterspec it is set to 20 the pulser To integrate these two peaks a special class of ROOT called TSpectrum is used This class is able to perform a peak search in a one dimensional histogram It does require a default standard deviation for the searched peaks a sigma of 20 is reasonable for the monitor spectrometer If one peak is found the y values of three times sigma in positive and negative x direction are taken and averaged This value is subtracted from the y value of the peak what defines the peak height see figure Mor03 Although the real standard deviation for the pea
90. ram is downloaded successfully it should compile without any errors as it https nuserv uni muenster de cgit cgit cgi MoS fitter git 46 5 2 The Monitor Spectrometer Analysis Software 47 does require the same packages as Kasper and createfilterspec When everything worked fine the program is able to fit a K 32 spectrum using the Doniach Sunjic model by default A fit can be started by running the fit sh script with the path to a createfilterspec output file as an argument It does not matter whether the output file is a txt file or a ROOT file The general settings for the fit program can be found in the setup txt To change fit parameters the user may edit the param dat Within this file the user can edit the fit boundaries set the source position which is usually derived from the ROOT file and set all the fit parameters and step sizes A detailed description of the fit parameters can be found in the manual Sle12 Another important setup file is the setup_root txt The user can specify whether data should be taken from the ROOT file recorded by the createfilterspec or the data from the fit program settings The fitting is based on the minimisation of the chi square function La peer 5 1 i 1 where x are the voltages y the count rates and o the error of these data points The function f x amp is a model function depending on the voltages and a parameter vector amp In the
91. ram is presented This version is capable to perform the same as the old program but also supports runs includ ing sub runs it can output all derived data into a ROOT file can handle offset source voltage detects line positions automatically finds peaks in the histograms automatically and is able to derive the source position as well as the source that is used The latest version can be found on the Git repository After the program is downloaded it does need Kasper which includes KaLi and the boost libraries as well as ROOT to compile To run createfilterspec at least one argument is required This argument is the run number of the desired run Specifying one argument makes sense if the run consists of sub runs else two arguments should be used the first one is the start run number and the second one the end run number Two arguments do make sense for analysing old runs that were not recorded with sub runs or if the user wants to analyse more than one run with sub runs But the user has to be careful as start and end run number need to be exact for runs without sub runs and in case of analysing more than one run with sub runs there may not be a run without sub runs in between As the third argument the location of a parameterfile can be stated The default is parameter txt in the home directory of the program The Parameter File The Parameter File contains the most important settings for the createfilterspec progra
92. rd bin ich angesichts der falschen Statistik der N und Li 6 Kerne sowie des kontinuierlichen 6 Spektrums auf einen verzweifelten Ausweg verfallen um den Wechselsatz der Statistik und den Energiesatz zu retten N mlich die M glichkeit es k nnten elektrisch neutrale Teilchen die ich Neutronen nennen will in den Kernen ex istieren welche den Spin 1 2 haben und das Ausschlie ungsprinzip befolgen und sich von Lichtquanten au erdem noch dadurch unterscheiden da sie nicht mit Lichtgeschwindigkeit laufen Die Masse der Neutronen m te von derselben Gr enordnung wie die Elektro nenmasse sein und jedenfalls nicht gr er als 0 01 Protonenmasse Das kontinuierliche B Spektrum w re dann verst ndlich unter der Annahme da beim Zerfall mit dem Elektron jeweils noch ein Neutron emittiert wird derart da die Summe der Energie von Neutron und Elektron konstant ist Wolfgang Pauli Offener Brief an die Gruppe der Radioaktiven bei der Gauvereins Tagung zu T bin gen Dezember 1930 Dear Radioactivd2 Ladies and Gentlemen The bearer of this letter I beg you to listen to graciously will explain to you in detail that I came in face of the wrong statistics of N and Li 6 nuclei as well as the continu ous B spectrum to a desperate solution to save the exchange theorem of statistics and the energy theorem There is the opportunity that electrical neutral particles I would like to call neutrons are
93. rights to write to ADEI control where it is necessary and desired Reading sensors with ORCA is possible from anywhere around the world using the standard external ADEI address i The external ADEI 3http katrin kit edu adei 35 36 4 Slow Control of KATRIN has the advantage that it can access all sensors not just the sensors read by ZEUS This address is saved into a variable that works the same way as the variable derived by the the find function The highlighted variable called VoltageChanVessel en ables access to the set value for the High Voltage Power Supply on the vessel at the monitor spectrometer 4 queueControlSetpointForChan argl value arg2 This is another IPE Slow Control function that uses the VoltageChanVessel vari able to access the control channel and queue values to that channel It uses two variables the first is the channel VotageChanVessel and the second one is the set value that is derived from the runList array It is also possible to write values directly to a channel of control with the function postControlSetpointForChan that requires identical arguments 5 sendSetpointRequestQueue This function does not require any arguments and sends all set values into the ADEI queue At the monitor spectrometer this queue has six entries Four for the high voltage power supplies consisting of the two set values and the set commands and the current line nu
94. rlsruhe refurbished and modernised If not stated differently this chapter is based on Kat05 3 1 Main Components PER EEE EFT gl 1 i UEH MMAM M m Rear wer ERBE cps Pre Focal Plane Section icra Detector Main Spectrometer with air coils Figure 3 1 Overview of the KATRIN experiment The setup has a length of 70m and consists of the source WGTS the transport section DPS and CPS the pre spectrometer the main spectrometer the detector as well as the rear section This figure is a modified drawing from Mell2 An overview of the KATRIN experiment and its components is given in figure 3 1 It consists of a windowless gaseous tritium source WGTS emitting the electrons that are detected at the focal plane detector FPD Before the electrons have to pass the transport section which is split into two parts the differential pumping section DPS2 F and the cryogenic pumping section CPS These are necessary to reduce the tritium con tent Afterwards the electrons have to pass the pre spectrometer it reduces the flux of the 17 18 3 The KATRIN Experiment electrons as only electrons with an energy above 18 3keV can pass The flux reduction is about a factor of 1076 The pre spectrometer as well as the main spectrometer are based on the MAC E Filter Magnetic Adiabatic Collimation combined with an Electrostatic Filter principle The reduced electron flux enters the main spectrometer where a
95. ron neutrino flux CDD 98 This experiment was the first evidence for neutrino oscillations In 1968 a paper from the Homestake experiment was publicized pointing out a low neu trino flux but it was not clear whether it is a problem caused by the standard model of the sun or the experiment and background suppression DHH68 Experiments for different energies of the neutrinos were done at SAGE and GALLEX SAGE was using the inverse beta decay also and was sensitive to low energy neutrinos from pp fusion EI01 The GALLEX experiment derived the same results 10 2 Neutrinos Hence there is a deficit of solar neutrinos In 2001 the Sudbury Neutrino Observatory SNO was able to measure all neutrinos from the ppllI process B as it was sensitive to all neutrino flavours by measuring the neutral current NC the gauge boson is the neutral Z boson in the following way Vy td gt ptn i 2 21 this is sensitive to all neutrino flavours with an equal sensitivity SNO did also measure the charged current CC the gauge bosons are W as follows Vetd pt pte 2 22 The CC is only sensitive to electron neutrinos Additionally SNO measured the rate of elastic scattering ES Vy te gt Vr te 2 23 This ES is sensitive to all neutrinos but the cross section for electron neutrinos is about six times larger than for the other neutrino flavours With these methods it became pos sible to calculate the total flux which is
96. rson and Frank McGirt at LANL Los Alamos National Lab in the 1980s Work on ORCA started at CENPA Center for Nuclear Physics and Astro physics at the University of Washington in 2002 It was written almost entirely by Mark Howe who was also working on SHaRC in the 1990s How13 ORCA is running on MacOS X and is written in Objective C using the MacOS X Cocoa application framework Its goal is on the one hand to create a data acquisition and control system general purpose software that is easy to use but on the other hand it should be highly modular object oriented and easy to develop and maintain To realise that the design pattern of ORCA is based on MVC model view controller In ORCA a model is an independent software module which can be a data analysis module a data acquisition task or directly a model corresponding to hardware The view is a user interface element that is displaying model s data while the controller passes data from the model to the view and user interface commands from the view to the model Usually one piece of model view and controller represent one piece of hardware HCHT04 For the ease of use ORCA has a graphical user interface that can be controlled by a computer mouse The configuration window is the main window in ORCA see figure 4 1 Initially it is empty and the user has to add new objects on its own or use pre configured setups Objects are selected from the ORCA catalog The user
97. rum 2 22 2 on nn nn 3 1 Katrin Beamline 2 2 22 oo Comm nen 3 2 Scheme of WGTS osaa aara nan aa paag eR DERRE aa 3 3 Transportsection with the DPS and UPS 2 2 2 2 2 nme 3 4 The Focal Plane Detector 2 22 22 Co nommen 3 5 Americium measurement FPD 2 2 2222 m on nn 3 6 Working principle MAC E Filtal seeks sree DERA EAEE ES 3 7 The monitor spectrometer 2 ooa a a e 3 8 Rubidium decay 2 ee 3 9 Magnetic Field Configuration Monitor Spectrometer 4 1 Overview of the experimental setup at the monitor spectrometer in ORCA 4 2 Overview of the server structure for slow control 4 3 The ORCA Slow Control Script at the monitor spectrometer 4 4 Behaviour of the High Voltage Power Supply 4 5 Behaviour of the High Voltage Power Supply 5 1 Overview of the server structure for data analysis 8 2 Overview of TSpectrum peak search 2 2 2 2 Comm nn 5 3 Filterspectrum of run 158542 2 2 Co oo moon 6 1 Line stability K 32 Pt30 5 2 2 2 oo aa 6 2 Line stability L 32 Pt30 5 zu 2 ee hee ee He 6 3 The dependency of the measurement time on the line position 6 4 The dependency of the error over time 2 2 2 Emm nern 6 5 Voltage oscill
98. s from the sun Neutri nos can only interact with particles through gravity if they have a mass what is discussed later and through weak interaction Due to a low coupling constant and a short range of the weak interactions humans cannot recognise the high flux of neutrinos But there are not just neutrinos from the sun Some sources for neutrinos are described within this chapter and their flux is depicted in figure 2 1 2 2 1 Primordial Neutrinos Shortly after the big bang the neutrons and protons were in a thermal and chemical equilibrium T gt 1MeV t lt 1s At a temperature of 10MeV and t 10s protons and neutrons were still in a thermal equilibrium through the weak interaction This equilibrium can be described by the following equations pte amp n re 2 3 pt tVe n et pte e on 2 5 The rate of n p and p gt n sinks rapidly with decreasing temperatures After about 0 02s the reaction rate is smaller than the expansion rate and the weak interaction freezes 2 Neutrinos oO S 10 9 H Q 10 neutrino flux ems MeV 10 10 10 104 10 1 10 10 atmospheric 10 10 neutrino energy MeV Figure 2 1 Overview neutrino sources and their energies The neutrinos with a high flux are derived from the sun and the neutrinos with high energies are at mospheric Except geo neutrinos which originate from radioactive isotopes on the earth the different neutrinos f
99. scussed in the next chapter see page 143 2 2 6 Accelerator Neutrinos Protons can be accelerated and shot on a target material like beryllium The targets are usually several interactions lengths long but should be as short as possible so the secondary particles cannot interact with the target material The resulting particles are pions and kaons During their flight they decay into neutrinos see equation 2 7 The neutrino spectrum is split into two lines On the one hand the low energy neutrinos from the pion decay and the high energy neutrinos from the kaon decay on the other hand The neutrinos are muon neutrinos mostly but they are contaminated with electron neutrinos especially from the decay of kaons what makes oscillation experiments more difficult see FY03 page 145 2 3 Neutrino Oscillations In 1998 first evidences for neutrino oscillations were discovered at Homestake Homestake is placed in a gold mine at Lead South Dakota in a depth of 4400m This depth is necessary to suppress the argon production by neutrons and protons The experiment is based on the inverse beta decay nee Arte 2 20 Hence the solar neutrinos induce argon into the chlorine detector The discovered rate was 0 478 0 030 stat 0 029 syst per day This causes a rate per target atom of 2 56 0 16 stat 0 16 syst 107364 but the expected rate is 9 3 1 3 10736 Thus the measured neutrino flux is too low for the expected elect
100. se 8 decay pt Ve gt ntet 2 2 The neutrino flux was gained by a reactor and the target were protons Afterwards the emanating neutron and the positron were detected The Hanford experiment had the problem of a huge background thus a succession experiment was required to prove the free neutrino It was using the inverse 8 decay also CRH 56 In 1962 a second generation of neutrinos the muon neutrino was discovered and in 2001 the tau neutrino KUATO In this chapter a detailed introduction to neutrinos and their origin as well as their prop erties is given 2 1 Standard Model The standard model of particle physics includes the weak the strong and the electro magnetic interactions An overview of these interactions and their gauge boson is given in table 2 1 The gravitation could not be included into the standard model yet But the coupling constant of gravitation is much smaller than the others and can be neglected This section is based on the book PRSZ09 As photons have no mass their electromagnetical interaction has an infinite range The gluon is massless also but the range is limited by interactions of the gluons with one an other In a distance over 1fm the energy of the field is very high and new quark anti quark particles emerge The weak interaction is limited to a distance of 10 fm due to the high mass of its gauge bosons The electromagnetic and the weak interaction can be combined to one interaction
101. ssel runlist 2 Voltage Source Voltage Voltage Vessel VoltageVessel Twait runList 3 if Voltage gt 858 VoltageVessel gt 33580 return Voltage too high 5 if RunControl off LineRun 1 RunControl setOfflineRun 8 VoltageChanVessel ADEI f indChanOfControl http 192 168 118 67 adei path monitorspec monitorspec 3 8 VoltageChan ADEI findChanOfControl http 192 168 118 67 adei path monitorspec monitorspec 5 8 SetVoltageChan ADEI f indChanOfControl http 192 168 116 67 adei path monitorspec monitorspec 13 8 LineChan ADEI findChanOfControl http 192 168 118 67 adei path monitorspec monitorspec 14 6 Fluke ADEI f indChanOf Sensor http 192 168 118 67 adei path monitorspec monitorspec 8 8 FlukeChanVessel ADEI f indChanOfSensor http katrin kit edu adei path mos MonitorSpec_rep F luke 1 runChan ADEI findChanOfControl http 192 168 118 67 adei path monitorspec monitorspec 14 1 ADEI queueControlSetpointForChan SetVoltageChanVessel value 1 ADEI queueControlSetpointForChan SetVoltageChan value 1 ADEI queueControlSetpointForChan SetVoltageChan value runList 6 ADEI queueControlSetpointForChan runChan value RunControl getCurrentRunNumber ADEI postRequestForChan Fluke ADEI postRequestForChan F lukeChanvessel 1 FlukeValue 1 ADEI valueForChan F luke F lu
102. ssionen ber Themen jeglicher Art Martin Slezak f r den vielen Spa mit LabVIEW aber vor allem f r den freund schaftlichen humorvollen Umgang miteinander Dr Till Bergmann f r eine tolle Einf hrung in ORCA und die sehr gro e Hilfe bei allen Fragen sowie dem KATRIX Projekt Suren Chilingaryan und Armen Beglarian f r die super Hilfe rundum Slow Control Marco Haag f r viele gel ste C Probleme und eine super KaLi Unterst tzung Mark Howe f r einen super Support f r ORCA Probleme jeglicher Art Und dem ganzen KATRIN Team f r eine super Atmosph re auf und abseits der Arbeit Meinen Freunden und meiner Familie gilt nat rlich auch besonderer Dank 79
103. stigation The same measurement has been done for the source power supply But this time no queues have been used the values are written directly to ADEI control with a 2s offset between them The outcome can be seen in figure 4 5 The slow control worked fine for two days but on one day slow control did not work reliable red triangles If the loss of data between the MAC and ZEUS cannot be solved it might be useful to introduce a Field Point object to ORCA that ORCA is able to talk to the Field Point directly which is possible as these are within the same intranet 10 current Voltage set Voltage V 104 20 P i l I 1 30000 35000 Voltage V l l l 1 1 l 1 10000 15000 20000 25000 Figure 4 4 The behaviour of the High Voltage Power Supply is shown in this picture From the 22nd of December 2012 to the 2nd of January 2013 the Voltage was ramped from 0 32000V in 10V steps On the x axis the set volt age is drawn and on the y axis the current voltage read by the K35 divider minus the set voltage is drawn The trend is on the one hand not linear and the measurement points at 10 and 20 volts are set values not set by the system about 14 Overall the graph contains 30898 measurement points 39 40 4 Slow Control of KATRIN gt Z CL 2 E 17 01 19 01 gt HM A A a A S 15 SF j 20 01 AA AA A A A AA aa aA A A AAA nd k A o 2 io N A f Fr A lik MM AAA A AA AMA A
104. surement control with LabVIEW which was proven to be convenient A so called scan is controlled by an appropriate run list which contains all required pa rameters The run list is read from a csv file which can be produced with most spread sheet programs Spread sheet functionality is very helpful to create run lists For each set of measurement parameters e g for each voltage step a line in the run list is required Institute for Data Processing and Electronics 33 34 4 Slow Control of KATRIN The parameters are explained below in more detail They are all stored in the database 1 Line Number The Line Number is useful for the analysis only it counts up and down for one line scan up down or down up 2 Voltage This is the set voltage for the high voltage power supply that puts voltage on the vessel 3 Waiting Time Defines the time between runs sub runs Within this time a new HV value is set and stabilized when properly chosen see 14 5 1 4 Run Time This sets the length of a run in ORCA and is therefore the measurement time Two additional columns had to be added 5 Voltage on the Source The slow control has to be able to set offset voltages on an additional Power Supply This is necessary during KATRIN measurements 6 Sub Run This option enables the user to control whether a new run should start or if the following set points do still belong to the previous run as a sub run If the user
105. t der verwendeten Quelle l t sich somit eine Aussage ber die Messdauer pro Quellaktivit t treffen F r einen Fehler auf die Linienposition unter 20mV darf die Messdauer Aktivit t nicht unter 16100kBgqs liegen Die experimentell bestimmte Transmission des Monitorspektrom eters ist nur ca 53 der erwarteten u ere Einfl sse wie zum Beispiel Temperaturschwankungen k nnen die Span nungsstabilit t der Hochspannungsnetzger te beeinflussen Dieser Einflu wurde untersucht und f r geringe Messzeiten pro Messpunkt gibt es keine gravierenden Einfl sse auf die Linienposition vii Contents Erkl rung Zusammenfassung 1 Introduction 2 Neutrinos 2 1 Standard Model 2 2 Neutrino Sources 2 2 1 Primordial Neutrinos 2 2 3 Supernovae Neutrinos 2 2 4 Solar Neutrinos 2 2 5 Reactor Neutrinos 2 2 6 Accelerator Neutrinos 2 3 Neutrino Oscillations 2 4 The Neutrino Mass 2 4 1 Double 6 Decay 2 4 2 B Decay Team 24 2er Rhenium 3 The KATRIN Experiment 3 1 Main Components 3 1 1 The Tritium Source 3 1 2 Transport Section 3 1 3 Pre Spectrometer 3 1 4 Main Spectromete
106. t the Monitor Spectrometer queueCurrent RunNumber val Puts the run number into a queue The run number is the argument get Voltage Vessel_V This function returns the voltage read by the High Voltage Power Supply in volts get Voltage VesselH VDivider_V This function returns the Voltage on the vessel read by the Julie Research Divider getSource Volt Meter_V This function returns the voltage on the source read by a voltmeter getSourcePosition_mm This function returns the position of the source in millimeters as an array and in x y z order getDetectorPosition_mm This function return the position of the detector in millimeters as an array and in x y z order getDetectorTemperatur Returns the temperature of the detector in C getPressureVessel Returns the pressure on the vessel in millibar getPressurePreVacuum Returns the pre vacuum pressure in millibar getPressureDetector Returns the pressure at the detector in millibar getPressureSource Returns the pressure at the source in millibar 75 76 Appendix e getLHeLevel Returns the liquid helium level as an array in the order of source detector e getLN2Level Returns the liquid nitrogen level as an array in the order of source detector e get AirCoilCurrent Has no function yet as it is not integrated into ZEUS 76 A Orca 77 A 3 Orca Slow Control Script at the Monitor Spectrometer import ORCARu
107. taken from page 35 De With these information the analytical transmission function of an isotropical emitting source can be determined 0 E qU lt 0 0 lt E qU lt AE 3 5 1 E qU gt AE with E as the energy of the electrons q the charge of the electron and U the retarding potential 3 3 High Voltage Monitoring The electrons of the tritium beta decay at the endpoint are filtered by the retarding voltage of the spectrometers Hence it is necessary to know the voltage very precisely Already little fluctuations have an influence on the neutrino mass A smearing of the retarding potential with a Gaussian variance g results into a systematic shift of Am 20 3 6 A shift lower than 0 007eV Zbo1lll results into an error of the voltage of lt 0 059eV which is a relative error of 3 17ppm at the tritium endpoint of 18 6keV 23 24 3 The KATRIN Experiment Figure 3 7 The monitor spectrometer This figure shows the monitor spectrometer in the building 461 at KIT On the very left is the source followed by the spectrometer vessel with the air coils and the detector on the very right At both ends of the spectrometer vessel behind the ladders the shielding of the solenoids can be seen This figure is taken from Erh12 Therefore the KATRIN experiment requires a precise short term stability as well as a method to guarantee the stability over years 3 17ppm Besides the precision the ac curacy h
108. ter file of createfilterspec This is the parameterfile for the createfilterspecv2 version Pulser on off Pulser Frequency Sigma for Integration Source Voltmeter Vessel Voltmeter Read Source Position Name Detector Pixel Number Draw Histograms Get Runtime from Pulser Set Peak Ratio Save filterspec in txt Use manual boundaries 1 200 8 446 REU 0 0101 446 REU 0 0003 Table A 1 The parameter file of the createfilterspec This tabular shows all entries and default values of the parameter txt in the createfilterspec home folder The settings for the manual boundaries can be found in integrationbound txt that is in the createfilterspec home folder also 78 Danksagung Mein Dank gilt allen die zu dieser Arbeit beigetragen haben insbesondere Prof Dr Guido Drexlin f r die spannenden Astroteilchenphysikvorlesungen die mich motiviert haben meine Diplomarbeit bei KATRIN zu schreiben Prof Dr Wim de Boer f r die bernahme der Zweitkorrektur und die Kosmolo gievorlesungen die mich motiviert haben freitags zeitig aufzustehen Dr Klaus Schl sser f r eine super Betreuung einem freundschaftlichen humor vollem Umgang und f r die qualvollen Stunden des Korrekturlesens meiner geistigen Erg sse Dr Joachim Wolf f r die Unterst tzung speziell zu Beginn dieser Diplomarbeit Philipp Rovedo und Moritz Erhard f r viele humorvolle Stunden im B ro den lock eren Umgang miteinander und viele Disku
109. the electroweak interaction 2 2 Neutrino Sources 5 Interaction Couples With Gauge Boson Mass GeV c weak weak charge w Z x 10 strong color 8 gluons g 0 electromagnetic electrical charge photon Y 0 Table 2 1 Overview on interactions in the standard model The table is taken from PRSZ09 Besides the gauge bosons the standard model contains fermions with spin 1 2 An overview is given in table 2 2 All fermions have their own anti particles with identical mass but op posite charge and color In the standard model are just three generations of fermions and from the Z resonance it can be derived that there may not be a fourth generation except one with a massless neutrino The standard model predicts a negative helicity for neutri Fermions Generation Charge Color Interaction I I MI Ve V Vr 0 weak Lept K Ten u T 1 electromagnetic weak Quarks i Hi i Fs r b g electromagn weak strong Table 2 2 This table shows the fermions in the standard model These are split into three generations The table is taken from PRSZ09 nos In 1958 Goldhaber Grodzins and Sunyar measured the helicity of neutrinos and found out that it is indeed 1 That means that there are only left handed neutrinos and right handed anti neutrinos coupling to the gauge bosons of weak interaction just as the standard model predicts 2 2 Neutrino Sources On the earth is a neutrino flux of 6 6 1010 cm s of neutrino
110. there is Sub Run Control where the user finds two buttons one to end sub runs and one to start new sub runs The last settings are the Run Options The user can execute ORCA Scripts at run start and run end set the Run Timer enable or disable the Repeat run button and checkmark whether it is a normal or offline 30 4 1 Introduction to ORCA 31 run offline runs are not saved Data Readout A 2 This object determines where the data is taken from It can also output the Readout Rate and display data that is read out but not yet processed in a histogram For KATRIN the data will be retrieved from a crate which is one of the IPE DAQ V3 the IPE DAQ V4 or the V4 Mini Crates the latter one is used at the monitor spectrometer These crates can be equipped with FLT First Level Trigger and SLT Second Level Trigger Cards Data Monitor A 3 The Data Monitor enables the user to take a look at data of all FLT channels 24 per card online When the user double clicks on one channel a graph is displayed that plots the counts on the y axis and the energy on the x axis The energy calibration has to be done manually in ORCA Additionally the Data Monitor has three options e Write IGOR Histograms If this option is enabled the Data Monitor will output the data to a file in ascii form Usually this is deactivated and not necessary for KATRIN e Ship Final Histograms This option accumulates all histograms until the run is fin
111. time it is necessary to derive a rela tion to the activity of the used source For this measurement Pt10 1 was used It is possible to derive the activity of the source from it in case no electrons are lost and all of them are detected Assuming a point source the ratio between the isotropic emitted 52 6 2 Least Required Measurement Time 53 gt 2 i central O u 04L first O last oO 0 08 5 gt S 5 0 06 5 0 04 S By Bs 0 02 5222222 eee 0 10 20 30 40 50 60 time s Figure 6 4 The dependency of measurement time on the line position error On the y axis the error on the line position in electron volts can be seen On the x axis the measurement time is plotted electrons and the electrons within the acceptance angle can be calculated as follows 2r 1 cos0 1 R Tk 5 1 cos 8 6 5 The angle 0 is the maximum acceptance angle electrons below this angle are accepted and above neglected It can be calculated as follows By sind Bmax 6 6 The ratio between the magnetic field can be derived from field cards by Oxford Instru T ments For a source position of 220 17cm from the analysing plane z axis this results in Bp 5 0 42 gt 9 40 4 6 7 MAT With an acceptance angle of 40 4 the ratio of accepted electrons is R 119 6 8 The electrons that hit the detector per second can be derived from the amplitude There fore also the loss ele
112. tion Chooz in France Double Chooz has two detectors one at a distance of 400m and one in a distance of 1050m The anti electron neutrinos from the reactor do not have the chance to change their flavour The distance to the first detector is too short for oscillations to occur region a in figure 2 4 the second one is placed at the very left of area b with an increased likelihood of a different flavour Hence if there are differences in the neutrino count at the second detector compared to the first one the flavour has changed Duo to a small probability of interaction the measurement time of the current phase is five years Dou13 The Daya Bay experiment consists of three detectors Two near detectors one is close to the Daya Bay core and one that is close to the LingAo cores The advantage of this experiment is that the reactor complex is amongst the five most powerful of the world Additionally mountains are nearby what eases background suppression Day07 The RENO experiment is placed at the Yonggwang reactor in South Korea The power plant consists of six cores The experiment is done with two detectors a close one and one in a greater distance on the opposite side of the reactor GTC12 The latest results for these experiments are 11 12 2 Neutrinos 1 L 1 1 amp b gt OE Sam pa ta Am OF e en 1 0 D P Vy Ver O 5 0 5 2 g g 0 O 1n Sn 5n 10n 20n Am L 4 E Figure 2 4
113. togram length for this run is two seconds For a better overview an offset of 0 2s on the x axis for the first and last histogram plot is used 59meV But this measurement time is not enough as a huge fluctuation of the line position can be seen for the central and the first histograms at about 18s Hence for low measure ment times the single histogram does have a huge influence on the line position After 30s the line position becomes stable and the fluctuations have averaged out Very interesting is that starting at the central histogram still causes huge fluctuations of the line position and starting with the last histogram gives a rather stable line position These fluctuations might be caused by the high voltage power supply for the vessel Al though the voltage for that run has been constant relatively huge fluctuations occurred and the standard deviation for the first half of one sub run was partially a factor of two different to the second half and the mean voltage up to 5mV different Within the scope of voltmeter accuracy these differences were not caused by the source power supply When taking a look at this data the statistical dependence of the measurement points have to be considered At low measurement times the influence of single histograms is large which can cause large fluctuations These average out at higher measurement times and the influence of single histograms becomes lower To give a statement to the required measurement
114. tp arxiv org abs 1109 0763v1 Ahn Chebotaryov Choi et al Observation of Reactor Electron Antineutrinos Disappearance in the RENO Experiment 2012 Online Available http dx doi org 10 1103 PhysRevLett 108 191802 S M Bilenky Neutrino History of a unique particle 2012 Online Available http arxiv org abs 1210 3065 J N Bahcall and C Pena Garay Solar models and solar neutrino oscillations New Journal of Physics vol 6 no 1 p 63 2004 Online Available http dx doi org 10 1088 1367 2630 6 1 063 Cleveland Daily Davis Distel Lande Lee and Wildenhain MEA SUREMENT OF THE SOLAR ELECTRON NEUTRINO FLUX WITH THE HOMESTAKE CHLORINE DETECTOR 1998 Online Available http dx doi org 10 1086 305343 J Chadwick Possible Existence of a Neutron Nature p 312 1932 Online Available http dx doi org 10 1038 129312a0 M Cribier W Hampel G Heusser et al Results of the whole GALLEX experiment 1999 Online Available http dx doi org 10 1016 S0920 5632 98 00438 1 S Chilingaryan Private communication 2013 Cowan Reines Harrison Kruse and McGuire Detection of the Free Neutrino a Confirmation Science 1956 Online Available http dx doi org 10 1126 science 124 3212 103 Daya Bay Collaboration A Precision Measurement of the Neutrino Mixing Angle 013
115. trol getCurrentRunNunber fcheck whether the Voltages are not above a certain value you can edit these values but check the Range of the Voltmeters before ee ee print The VesselVoltage vesselVoltage is too high print Returning without changing the Voltages return if sourcevoltage 858 print The SourceVoltage sourceVoltage is too high print Returning without changing the Voltages return to be on the safe side we do not send every value to ADET control on its own but in a queue these queues are created with pre defined Furl queueCurrentLineNumber l ineNunber queueVoltageSource_V sourceVoltage queuevoltagevessel_W vesselVoltage 37 queueCurrentRunNumber runNumber RRSEKKSSSRVARREERESSES HRT ORES cmyanaune 39 finally the queue is sent 40 SendADEIQueue 42 now the script is waiting for the setvalues to be changed sa Steen aitTine Figure A 6 The Orca Slow Control script This script was used till December 2012 at the Monitor Spectrometer The latest version can be found in A Script Parameters Run Length Sub Run Run State REMMI r GE O Random Order Execute 1 times Execution count 2 of 99 feu Gave To File Read From File Read From File File Last File Desktop Measurement 10 01 2012 09 29 38 AM csv da Figure A 7 The Run List The Run List reads Run Control files made b
116. tween them The normal beta decay has a broad distribution 2me lt E lt Emaz The double beta decay does have a distinct peak at E Ema from which the neutrino mass can be derived The normal double beta decay was observed in 1987 for the first time There is no proof for the neutrinoless double beta decay yet The double beta decay is expected for an instable nucleus A Z if A Z 1 has a higher mass than m A Z This makes a normal beta decay from A Z2 gt A Z 1 impossible Fur thermore the mass of A Z 2 has to be lower than the mass of A Z This can happen if the nucleus A Z is an even even core ee core A Z 1 is an odd odd core 00 core and the core A Z 2 is even even again 14 2 4 The Neutrino Mass 15 If the neutrinoless double beta decay does exist it means that physics beyond the standard model does exist and the lepton count is not conserved It means also that neutrinos must be Majorana neutrinos v 7 Additionally the helicity between the vertices has to be adjusted This can happen in two ways first there is an additional right handed current at the weak interaction hence neutrinos with the wrong helicity can occur at the vertices But this is not that interesting for mass measurements The second possibility is that neutrinos have mass which is shown in the previous chapter and these can change their helicity and these can be right handed with a likelihood of W 1 e x ze 2 41 If
117. uerung In Zukunft soll es m glich sein den kompletten KATRIN Messbetrieb automatisch zu steuern Hierzu wurde am Monitorspektrometer die Prozesssteuerung von einem externen LabVIEW Programm in ORCA integriert Die Steuerung funktioniert ber ORCA Scripts Die Setzwerte werden ber das Interface ADEI control auf ZEUS ZEntrale datenerfassung Und Steuerung geschrieben und erreichen von dort aus den compact Field Point welcher direkt mit den Endger ten zum Beispiel Net zger ten kommunizieren kann Die Istwerte werden auch von diesen compact Field Point ausgelesen und von ZEUS in ADEI geschrieben von wo aus sie vom Endnutzer abgerufen werden k nnen Ein Run wird mit Hilfe der Run List welche in der Lage ist vorher in das csv Format exportierte Messteuerungsdateien einzulesen gestartet Die Run List ist mit einem ORCA Script verbunden welches daf r sorgt dass die entsprechenden Setzwerte gesetzt werden Nachdem dieses Script beendet ist wird Run Control gestartet welches mit der Auslesehardware des Detektors kommunizieren kann Der abgeschlossene Run wird auf der lokalen Festplatte gespeichert und ber ein Skript auf einen Server am IPE Institut f r Prozessdatenverarbeitung und Elektronik transferiert und ist dort als ROOT file oder als original ORCA Ausgabedatei f r den Endnutzer zug nglich Im Rahmen dieser Diplomarbeit wurde der Messbetrieb auf Sub Runs umgestellt Diese erm glichen es den kompletten Scan einer Linie in einer
118. urement from 22nd of December 2012 till 2nd of January 2013 about 14 of values have not been set Within 6The summed histogram contains histograms between sub runs and histograms at different voltages hence no conclusion can be derived from this histogram http www arachnoid com abouttime index html SIP 141 52 8 18 38 4 5 Problems and Solutions 39 this measurement the high voltage power supply has been ramped up and down from 0 32000V in 10V steps every 10s To change the values a queue with the set value and the set command is required The set value from ZEUS and the current value K35 divider are read back About 13 39 of set values have reached ZEUS but these have not been set these are the points at 10 and 20 V To check whether this problem has been caused at ZEUS and the Field Point or whether the set command as the second entry in the queue a second measurement was done This has been done from the 4th of January till the 10th of January and just two values in a queue have been written to ZEUS The outcome is that either both values do reach ZEUS or both are lost The loss rate from the slow control MAC to ZEUS is 0 08 and during the christmas measurement 0 26 On the one hand this outcome shows that using queues does not guarantee a success in changing Slow Control values and on the other hand that there is a problem between ZEUS the Field Point and the High Voltage Power Supply Both do require further inve
119. using Reactor Antineutrinos at Daya Bay 2007 Online Available http arxiv org abs hep ex 0701029 G Danby Gaillard Goulianos Lederman Mistry Schwartz and Steinberger Observation of High Energy Neutrino Reactions and the Existence of Two Kinds of Neutrinos American Physical Society 1962 Online Available http prl aps org abstract PRL v9 il p36_1 63 64 Bibliography DHH68 Doul3 Dre10 E1101 Erh12 Fer34 For13 FYo3 GGP o6 GGS5s Gil12 Goul0 GTC12 Haa12 Har12 Har13 HCH 04 Davis Harmer and Hoffmann SEARCH FOR NEUTRINOS FROM THE SUN 1968 Online Available http dx doi org 10 1103 PhysRevLett 20 1205 Double Chooz collaboration Homepage February 2013 Online Available http doublechooz in2p3 fr Public German welcome php G Drexlin Physik 6 Kerne und Teilchen Vorlesung 2010 Online Available http www ik fzk de drexlin S Elliott A Brief Description of SAGE 2001 Online Available http ewi npl washington edu sage M G Erhard Untersuchung der Langzeitstabilit t des nuklearen Standards f r die Energieskala des KATRIN Experiments 2012 Diploma Thesis Karl sruhe Institute of Technology E Fermi Versuch einer Theorie der 6 Strahlen Zeitschrift f r Physik pp 161 177 1934 Online Available http dx doi
120. ux is reduced by a factor of 1078 This is necessary to reduce the likelihood of scattering electrons or residual gas molecules which leads to an increased background In the past the pre spectromter served as a prototype for the main spectrometer 3 1 4 Main Spectrometer The main spectrometer is a vessel with an inner diameter of 9 8m and a length of 23 28m This results into a volume of 1400m and a mass of approximately 200tons The electrons coming from the pre spectrometer have a flux of 10 s these are guided adiabatically by a strong inhomogenous magnetic field see MAC E Filter page 21 that is generated by two superconducting solenoids The huge proportions are necessary as the flux tube expands to a diameter of 9m in the analysing plane in the center of the vessel Additionally to the superconducting solenoids air coils will be used to compensate the earth magnetic field and to allow fine tuning of the inner magnetic field The KATRIN experiment is aligned with an inclination of 15 with respect the south north axis The tank is made of stainless steel sheets A potential of 18 4kV will be applied to it The 19 20 3 The KATRIN Experiment Figure 3 3 The transportsection with the DPS and CPS On the left side the DPS can be seen figure taken from Stul2 and on the right side the CPS figure taken from Gill2 inner double layer wire electrodes will have a potential of 18 5kV respectively 18 6kV for the inner wir
121. xperiment 0 8 19 A 8 8A 19A Ty 3 0 6 T 0 4 0 2 a a Um Zu cum a u B T 0 4 LS 4 0 6 detector at z 2 3m Bean ie det segment 1 ee det segment 2 LS 1 LS 2 LS 3 z m 0 8 a rr 2 1 5 1 0 5 o 0 5 1 1 5 2 Figure 3 9 Magnetic field of the Monitor Spectrometer This figure shows the magnetic field of the spectrometer and its components Towards the outer wall the wire electrodes and solid electrodes can be seen On the very left and right are the superconducting solenoids and in the bottom and top the air coils with its currents can be seen This figure represents the spectrometer still in the Mainz setup It is taken from Th 07 stepped and arranged cylindrically That means that the distance from top to bottom electrode increases towards the analysing plane from both sides The wire electrodes are arranged as a bilayer in the analysing plane and narrow cylindrically towards the solenoids The monitor spectrometer was designed to apply different voltages to the solid and wire electrodes This is very useful to prevent charged particles from the outside for instance cosmic radiation to hit the outer wall and produce secondaries that can enter the flux tube The hitrate at the monitor spectrometer from conversion electrons of the source is very high for this reason both electrodes are set on the same voltage 3 4 3 Solenoids At both en
122. y the user It sends the Slow Control data to a script and is able to access Run Control 73 74 Appendix AOC IPE ADEI Slow Control 1 SS OES Channel Table Load from File Save as Chan Path or Name Value LoAlarm HiAlarm Lo Limit Hi Limit Type URL Standard Ops Statistics Request Queue i Te SE Path Name Print Items Poll every 10 sec Read Now o monitorspec m 0 o 100 o 100 Co http 192 168 110 67 adei 1 monitorspec m 0 o 100 o 100 Co http 192 168 110 67 adei 2 monitorspec m 27500 0 100 0 100 Co http 192 168 110 67 adei 3 monitorspec m 0 0 100 0 100 Co http 192 168 110 67 adei 4 monitorspec m 11421 0 100 0 100 Co http 192 168 110 67 adei 5 monitorspec m 11421 0 100 0 100 Co http 192 168 110 67 adei Details lt Nothing Selected gt O Ship Data View in Web See Web View See ADEI Tree Selected Item Setpoint 1 Set Send Queue Ey Figure A 8 The IPE Slow Control object This object grants access to ADEI and enables the user to read sensor data and write to control channels In this figure all control channels necessary for the Monitor Spectrometer are show These are highlighted in red Catalog Data Flow Host Vme CAMAC IPE DAQ cPCI PXI HV GPIB USB Serial Ethernet Motors Misc Process Experiments IPE KATRIN IPE V4 KATRIN Edelweiss gt i u IPE Slow Control I BR ms ge 3 IPE DAQ V3 crate

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