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Manual Preamplifier SP883d - Nuclear and Particle Physics

1. 1x Bochum 10x Bochum 52 Bochum 66 Bochum 30x Proto192 2 Stockholm 2 Giessen 120x Proto192 10x Bochum delivered 50 Bochum also for SP883a02 as APD Adapter Protos un RES SP917 Single APD wee EIE SP917c d Dual APD Paralleled ithout Filter Barrel 20 Crystal Barrel D o N o n SP883d_Manual_Preamp page 50 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Low Noise Low Power Charge Preamplifier Family overview Accessories _ID Nr Application Description Status Application SP883a Singe APD Z o Prototyp SP88838a SingeAPD qusenolonger Improved stability power supply Pee Sa SP883a02 1kV Single APD___ New rectangular APD higher bias voltage 1 y SP883b_ Quad APD 4848mm SS 1kV with HV Filter for glass housing VPT 18x48mm aUe SP sc Dual APD o Crystal Barrel Implementations Delivery Model SP883d without model SP883a02 Deliver Pieces Version SFr ee ee ee July August 2011 j 96 APD Bochum Proto 192 Contribution Basel group costs for material for Proto192 detailed list separate 2011 Matrial Costs CHF 266 Stk Preamps for VPT T APD and Adapter PCB s etc 10 000 70 Capsules for APD mountino 5 00
2. i ats wi i e Qe s24 s A zi i Bes gS Ll ki ri s TAG ie 11338 pse gs 5 5 E a P ZEE i Ale se came 12 hp Lp ia HL V a la ge ae i a FE 38 s E I ET 8 E B E a 8 p gt r E I g g E i s a eg gt i cr gg Tiny So m 1 985 feat Dan 85 DE mi 8 H E Bie H ert 22 pod s 287348 D 4 m uu E i 28 Aj LL Se gm 28 of E qe ae a T3 11 Seu Raa a i 22 i T ze E E E P E Abe ge i als g m 1 i i geese g d AG Ge of weet i pisi andres Physics Uni Basel CH 4056 Basel Die page 19 of 55 300pF fast gleich aber de Bias Spanmmeg liegt h her typ 6301 F r ltere rechteckige LAAPD bleibt die Kapazit t 500V Deshalb wurden die HV Filter C s auf 1EV P itt teilweise wurde 2050 verwendet schlechte SP883d Manual Pream Ell 0 statt 15M time constant C15 100pF satt 47pF Compensation Cll C12 1000V satt 5001 EX SE statt 10M BS 100k satt IM Verhalten Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Wiring 8 Assembling Differences between SP883d Prototypes and Serie Version On Prototypes the LV Filter and Pads for wires were on the thin PCB For series this LV circuit was moved to the thicker Amplifier PCB to enable the possibility to use it autonomously for APD s This increases also convenience for assembling Wiring for series
3. Shaping Time jus SP883d_Manual_Preamp page 38 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Possible additional shaper feature options are e Signal polarity inverting neg output and or differential driver to fit the ADC from Pawel Marciniewski e adj gain compensate VPT T gain multiple gain ranges dynamic range e scaleable peaking time optimised in relation to the rate e Baseline restoring Note Peaking time defines the time the signal reaches its peak amplitude Peaking time depends on integration differentiation time but is not the same as the integration time VME crates with switch mode power supply usually generate more noise than NIM Crates both radiated and conducted Good filtering of the power supply tracks and shielding is important The old KVI shaper VME module A 16ch Shaping module was developed at KVI Frans Schreuder in 2010 MODO111 and 10pcs were produced Powered by a VME connector has to be modified Performance The peaking time of 100ns results in too high noise Crosstalk of around 10 Titie Panda Shaper stage dual galn Date 19 oct 2010 DA d 1 1 A comercially available 16ch Shaper NIM Module is the Mesytec MSCF 16 The new KVI shaper circuit for implementation on the ADC pue y Ihre Ad f Im PER GND AE proa jmnE Moone 9 amp h Pn i
4. Note Passive Preshaper to shorten the pulse is not implemented because this changes signal energy amplitude frequency dependent and output impedance and is therefore not well suited for the use in Panda SP883d_Manual_Preamp page 39 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version C1 R 50 Ohm C Open drawing KVI SP883d Manual Preamp page 40 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version ADC Uppsala Pawel Marciniewski 100x162mm Input matching via Shaper Wiener AVM16 2V 500 single ended Input with Proto 60 the peak sensing ADC CAEN V785N in combination with Mesytec MSCF 16 has been used Overview WienerAVMi6 Struck SIS9967 _ Struck SIS3301 CAEN V1724 channel 8 rr B8singeended 500 Memory O E 2x128kS ch S 15 19 5V 5V14 5A 12V 0 2A_ Wiener AVM16 Input circuit VCC O COMMON LEVEL lt gt ADCp 100nF r ADCn V TEST PULSE Figure 2 Input symetrizing amplifier and anti aliasing filter R5 R7 C2 Matching single ended to differential signal conversion Analog Devices AD8137 AD8139 500 Input OV to 5V Vom Vagr 2 75pE NPO Figure 5 A OV to 5V single ended driver 201 1 LTC640 97 l Single ended to differential signal conversion with integrated LP Filt
5. 0 3V Ga 3 BF862 N TR 0 25W 1 qp Ql 6V T 2 2ms 50R 10M 500V Photocathode K to GND 1 a gt BAS4SAL SD Bs de an 0 3V ca 50mm X m mA ANG li Em Lb sm4 A GD R9 cls y GND pulse gt Photocathode K 6V Hamamatsu Smm e 100pF COG 100pF compensation capacitor me m E k Compensation Y best for 0 100pF detector I capacitance lpF feedback I E R10 c10 47pF for 270pF APD Anode GND i lk E TuF LOY Tantal Cathode ca 630V a 1 e Rl4 z GND i Low noise floating power supply gt SV 3ijelded 2 twisted pairs cable Gain C13 loF Prec NPO E 6V 1 S x z Anmerkungen Version SP883c d Ad mean 10M 15M 100pF ber OP verbessert Stabilit t u Quiescent opt 0 Ohm 33R 470R rauscht weniger als 200R 300R p Sect power typ DecayTime Rx0 25us a 500kHz small signal BW 6V weniger pile up aber 8 2V stabiler bez Schwingen SW x l00mW y fm g ger pt e up 2 optical test circuit V 63mA gt 6V opt DecayTime RxC 10u fea Eingargsschurzdioden BAS45AL rauschen wenig lichtemp ndlich ca 4V pulse I gt 1 tm 100R f 1500V C bei Wid ist kurzzeitige Uberpanmmg zul sig SV 1 2mA Filter amp protection Pile up reduction tradeoffs 1 3 MHz IF statt luF am Ausgang LED Pulse typ 10ns inmh current limiting Higher noise Kovdensator Dielektrika X wg Temperatur fium bine e Higher power consumpt
6. Application Hints for best operation 11 Trouble NO Oe 219 CUERO REP ais al as e a os 12 Comparing noise measurement resultS oooooo ooo o eee eens p Noise measurement setup ee ee rs 13 Example Noise measured with shaper and oscilloscope eee ee ee eee 14 Schematic diagram SP883d for VPT VPTT 15 Differences between the versions of SP883d_PS VPT VPTT 1 5 Circuit component function description oo o oo o s 17 VVIFING ASSOMIDINNG citissime aa aaa 20 Differences between SP883d Prototypes and Serie Version eee eee eee 20 Wiring TOr Serl amp s Version sse xu ace Reo 2 ed A oe bw a eles AA 20 1 Connecting wiring of power Supply 2 2 cc ee ee ee ee eee eens 24 2 rose Trece 21 3 VPITI CONNECCION sca dient aoa ME NA TR Indis OS o E A 24 4 Assemblindg VR WW VR TT Sat ge RE rtu o ER DE rt E c CIR B te RU 22 5 Adapter PCB for Dual APD crystal oo ooo o 24 Distribution of Power Supplies seus 31 nh XU LIT D CPI LUTTE E ND cal FUE TOR TOU 192 ee RS a OA E AR eet it Sa ca hts 31 WON EON Ol 33 Options 10V 2V Operation sur sa ur er Rn BR Sh co Ee Ban 39 PUISE PTOCESSING
7. Basel Preamp is a discrete charge preamplifier which has an excellent noise performance in combination with low power consumption It is designed for the readout of Photodetectors for the Panda Electromagnetic Calorimeter EMC The Photodetectors LAAPD VPT VPTT are attached to the end face of the lead tungstate scintillating crystals PW O II which have a typical geometry of 200 x 20 x 20 mm In comparison to a photomultiplier theses photodetectors are working better in a strong magnetic field Further the vacuumphotodetectors as Vacuum Photo Triode VPT and the Vacuum Photo Tetrode VPTT are better for high radiation which occurs in the center of the forward endcap than the semiconductor device LAAPD Therefore the barrel and the backward endcap of the EMC is equipped totally with LAAPDs and the forward endcap works with VPT T s and LAAPD s dependent of the region These devices act as photo detectors converting the scintillating light to an electrical charge Then the LNP Preamp linearly converts the charge signal to a positive voltage pulse which is transmitted via a 50 Ohm line to the subsequent electronics Since the complete EMC including the preamplifiers will be cooled to 25 to increase the light yiel d of the PWO II crystals the power dissipation of the preamplifier has to be minimized Low power dissipation leads to a smaller cooling unit and thinner cooling tubes it also helps to achieve a uniform temperature distribut
8. Capsule The capsule works as mechanical interface for the APD s to the crystal When mounting the APD s into the capsule take care because the capsule reaches around 0 2mm over the APD Material for Proto192 milled from POM later for better radiation hardness PEEK is foreseen Note The HV is soldered directly to the PCB placed around the center of the PCB between the preamps To save cabling only one HV is available for both APD s Therefore they must selected for gain conformity The cabling for LV 6V can also be reduced when both preamps are interconnected The capsule and the Dual APD PCB can be integrated optionally for high volume production as one unit made from Epoxy FR4 as a 3D PCB Also space can be saved that way The two holes with 2mm diameter are connected to GND and can be used to mount the copper tube or similar Connectors Contacting the preamps to the Adapter PCB SP883d APD is achieved by soldering the boards direct with a rigid wire or a 1 pin connector f e Farnell 972 9151 For SP883a02 long use 0 5mm rigid wire or 1 pin of the Fischer Elektronik MK LP 43 Note Solder the pins on the component side because on the APD Capsule side is no space for pins or solder joints So cut the pins in a way that they do not reach out of the PCB afe 5H H 0 or alternatively with a connector Board to Board 8 contact single row 2mm pitch connectors male 90 THT fem
9. glue Subtract noise floor of equipment measure test setup without preamp Calibrate signal chain with 1V signal pulse or LED Pulser or Gain of photodetector Multiply with gain of shaper Temperature Decide cooled at 25 C or at room te mperature Grounding of preamp if only via signal coax multiply with a factor of around 1 5 Shielding 5 6 side metal neighbourhood FL lamp PC VME cooler pump etc SP883d Manual Preamp page 12 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Noise measurement setup Noise R M S SQRT measured value noise floor Noise p p viewed on the oscilloscope is approximately 9 times higher than the real rms value Nx XXIX RN Noise measurement setup oe Test Beam MAMI and or 25 C 50mW Outside Beam Room Temp Note Use same power ground earth for all instruments RMS Histogram Test pulse coupling circuit 1 l l l j l I j l j I 4 I UN lt 500kHz Linear Power Supply NIM J II B kS 4 x Sensitivity 1V into 1pF is 1pC which gives 1V after OpAmp and results in 0 5V pC 500 ek Run 10 0MS s Tr Sam 111 1kHz 103 1kHz Hs StdDev 3 31mV gt gt C1 Ampl 0v Unstable histogram ner i CtAmpl OV Unstable histogr
10. time measurements Single range reduces ADC channels cost power space Driver for signal transmissions integrated drives 50 Ohm standard coaxial cables e Easy operation Power supplies LV HV in gt Signal out SP883d Manual Preamp page 1 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Table of Contents F9 to refresh Manual Datasheet Preamplifier SP883d 1 PrECA LUNAS LATE QUU dS Oda CUL a ode AAA e oa 3 Concept of the Panda Electromagnetic Calorimeter EMC readout 3 iguqeellinin iva PET rr TIR 4 Panda EMC Forward Endcap Proto 192 192 crystals red marked part 5 Main Endler GOS ie are En A ES EI RD nen 6 FAmilyorENP Preampliiiersz22 u22s 42 een bene a be SM 6 Pnotodelecto Susini anna 8 a Hamamatsu Triode R11375MOD3 eee 8 b Hamamatsu Tetrode R11375MOD ooooooooooor es 8 c Hamamatsu APD 88664 1010 and 811048 rectangular datasheet available 8 Oa le revodowvPnbjsxax sus aee bees dear Mea Bere acc ap Sob baaa es 8 e Hamamatsu Triode R2148 metal short llle 8 short Data type SP88998 5 0 i 9 General remarks for operation eese eere reee ene 10 Pwer UD DIOCCOUI Cis 353 5 4 4 3063 Soda AO RR DSL os T cac e a aha 10
11. 1 8mm coax cable via ITT Cannon 055 939 9039 AR6 available at Avnet Express or Newark Part Number 95F6346 For RG174 22 8mm via 055 939 9049FCD Farnell 121 5645 2 54 Another solution for connecting the coax shield is to solder the shortened shield of the partly dismanteled cable to the testpoints keystone test points compona ch 220 202 and the inner conductor direct to the PCB 2 Isolation There is high voltage on the board and the VPT T Isolate for up to 1 5 kV Isolation can provided by shrinking tube or plastic tube 3 VPT T connection a Because the original semi flexible wires from Hamamatsu for the R11375 are not delivered with a socket and therefore not constructed for space critical use Because of the advice from the manufacturer not to cut the pins and not to solder near the glass body we preferred flexible litz wires but nevertheless it is not the optimum to save space in depth Anyhow due to the fact that the manufacturer cuts and solders the pins of the tubes close to the glass body as they are delivered in fact there is obviously a possibility to connect them in a much better way but it has to be proceeded very carefully oolder the pins for A P and K of the tube directly to the solder points of the preamp and bend the Dynode pin under no force at the glass take the pressure off the glass with pliers in a way that a short wire can be soldered to the PCB This is the most space saving solution and
12. 1200V Phatocat ode E to GID Hamamatm VPT T diffsram pin 5 g BASAL rauschen wenig lichtsmpfindlich 1500V C bei Wid ist kurzzeitige berspammung zul ssig IF watt luF am Aus Kondenator Dielektriks X we Temperatur K10 18k f r 200u4 an SV fer Kurzichlussichscheit e Geruungwersmiderst nds anpassa derstand mot kurze Leitung OE out zu 47R weniger Schwingneigung bei K paz Laz Feedback C bobsze Kspazitit miedriger Gai Filter auf aim HV Filter in diexm Zusig wurde bewaut verzichtet Elektromiklabor 2 17 Institut f r Physik der Universitat Basel Klinge Dergarase 42 CH 4036 BASEL 70 Low Noise Low Power VPT T Q PreAmp P Very good shielding muz be provided to inmre lew nctw operatica via Different mounting holes cable shields Supply GND higher voltage drop on H Filter ATP CNTY DINA wee u 2 Gries Lan Feedback time constant z B 2MHza 253 bemar f r Bursts I 1 tv sy I D l Semsitivity IV into pF is IpC which I geas tos IV max ca SV PY Rd Pepper ep apply tor to i Eo 270pF shaper 250ns 2us Qip hx Ui Vasa 10 1 SE 19 Noiw Elektronen zem twin noise cf around JW ZB Noise in mV Std Dev x 1000 1L 6 Elektzomen low shielding box 1 2 3 SP883d_Manual_Preamp page 16 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Circuit component function description The circuit
13. 2011 tests are proceeded with a beam of 15GeV at CERN October 2011 in Bonn and 2012 in J lich Distribution of Power consumption Most of the heat produced is coming from the FET The power from the signal output is distributed half on board and the other half on the receiving side over the 50 Ohm resistors 180 D wu 4 OR WR i i i i n 1 amp 4 i i i 1 ri i E ri id 1 1 1 1 1 if 1 H 1 1 HO E 1 f H i ova 140 SN Oe eh ened ieee Er A A A O a E ee A O A A Cre O 1 1 1 1 1 1 1 1 1 i 12 01 1 1 1 rom d d 4 a 1 1 E 4 7k i rs z i 1 a i r1 a iod i 4 i 1 1 1 t 1 1 H 4 4 H 4 a 43 i i MEE Ld 1 LONE nS RS at i 3 TO MES NR 120 asa anni TS i parepta o naa e doa rr ne a aos e a O ania ec anra sa pad pias ded i 1 1 i 1 i 1 i H 1 Ka dou 1 i 1 Eo 404 i i i i H i H H i kan Tu 1 i H i i 10 m E E SUP uf Power dissipation on LNP Preamplifier a maximum possible energy worst case i i H A i a H i E t i MET yi bh 1 i 1 i i 3 EF 4 i 1 1 1 kd 1 1 1 i i asr i i i i 1 i 60 a TEEN Ory erent er test TTT ete EEES ert rere i 1 1 i 7k 74 F i 1 E ie bed al measured power dissipation mW a rin on E E EA EE is E o aa oda du HA p d d Pid bb tox 3 DEG 10 10 10 10 continuous event rate 1 s Figure 11 Power dissipation as function of continuous event rate for the LNP preamplifier red area FEI S Left Prototype SP883 Right simulation quad version SP883b Proto
14. 300 e gus which is in very good agreement with the measurement Notice that the temperature of the simulation as well as the noise measurements is performed at 25 C Nieagurediimulatad LHP FPreamplfat Molise VS Detector Capacitance Cd IS T 16500 7 7 T D i i j i i i 0 En 100 150 an 2c 20 2 C4 pF Figure 6 The left graph displays the PSpice simulated integrated output noise of the LNP Preamp for different detector capacitances from 0 pF 330 pF The right plot shows the simulated ENC versus the detector capacitance dashed red together with the measured ENC blue line both at 25 C Over the whole capacitance range the simulation and the measurement are in very good agreement SP883d Manual Preamp page 34 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Gain The gain was set equal for all models In peripheral regions of Proto192 and FW endcap APD s are used The gain for these photodetectors is typ 50 max 100 If the bias voltage is individually regulated for both APD a wider range can be covered in each crystal For use with APD with high gains the gain of the preamp can be reduced through changing the feedback capacitor from 1pF to 2 pF but the compensation capacitor must then also be changed from 47pF to 100pF to maintain stability at lower temperature With VPT T in the center of the FW Endcap the output si
15. Je 9 B e a E E vi Eu Mm 2 ou v wv i l o J o in dcs in le de JO EN Ini S S E Z e lo x x Pulse Function 9 Noise 25 C 50 R F 6V 6MA ORTEC 450 MV RMS MV Rms NA 6V 1MA KALIBRIEREN HisTOGRAMM Sn Dv Sm DEV SERIAL No POWER PULSE Noise w NOISE w LEAKAGE AUSLIEFERUNG CONSUMPTION FUNCTION VPT 270PF CURRENT BEMERKUNG REP JUNI 09 TYPICAL VALUES 1 ok 10V 1 19 EE Including noise floor of oscilloscope and shaper 0 5V rms Tek Run 25 0MS s Sample 1A 51 23kHz la 56 95KHz Hs StdDew 1 01mY TE el Y 7 E OMV 10 08 46 15 SP883d Manual Preamp page 44 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Reliability Quality e 100 of the parts are tested for their function but not for all parameters f e temperature e After Testing every unit gets its own serial number It is a number beginning with 1 manually engraved on the PCB e We have not used leadfree solder to improve the long time continuous low temperature 25 C operation We used a traditional Sn Pb 60 40 alloy e Do not use halogenidated or chlorinated cleaning solvents as f e Trichlorethylen to prevent damage of solder joints through activation of tin pest We use Inventec Topklean EL 10F for SP883d amp Elma Clean 225 Sonic for SP883d PS e Universal conformal
16. Michael Ste P al September 2006 Signal to Noise ratio 25 mm d 18 5 mm RIE FEU 190 VPT CMS ECAL S N Comparison VPT d LAAPD 10 mm n Hamamatsu 58664 1010 Signal AM QE 0 123 Signal comp to LAAPD Signal normalized to 1 LNP Preamplifier Noise LNP Preamplifier Noise 0 110 Tot Noise comp to LAAPD Tot Noise normalized to 1 2 S N is almost the same for LAAPD and VPT Michael Steinacher Physics Basel May 2008 CH 4056 Basel Physics Uni Basel page 36 of 55 P SP883d_Manual_Pream Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Noise vs Cooling vs detector capacitance Data from Panda TDR March 2008 with SP883a02 e An u m CO oe 1000 BASEL E LNP Preamplifier Noise VS Cd LNP Low Noise Low Power Measured LNP Preamplifier Noise VS Detector Capacitance Cd Equivalent noise char ett JA 10 05MHz 11 46MH2 5 00 e Shaping with a peaking time of 650 ns iT 1400 s 5 0 SS ve 0 100 200 300 amr Detector capacitance pF 600 f Figure 14 The measured noise performance of the LNP as function of the Umpeem Te TO detector capacitance Cg at room temperature and at 25 C Measurements gr en E 71 25 27 E m are performed by using an ORTEC 450 Research Amplifier with
17. PCB for Dual APD crystal For short preamplifier SP883d might be usefull also for long version SP883a02 An additional ca 18x18x1 6mm depends on capsule double sided PCB was built Features e Protects the APD Pins when mounting dismounting from the crystals e Planar mounting of the APD frontsurface equalize differences through mounting aid then solder and glue it to the PCB Holds the two preamplifiers to the capsule Holds HV Filter and Connector for APD Connection and filtering for both HV s GND Plane of Dual APD PCB is the 6 side of the electromagnetic shield Could be soldered to copper tube via two 2mm holes Temperature shield decoupling radiation barrier similar as in Proto60 Glueing the APD to the PCB maybe with an additional soft silicone sheet removable Photo left two short preamps SP883d prototype DualAPD PCB 20x20mm old quadratic APD in a socket cables Photo right two short preamps SSP883d dual APD adapter SP883d_APD 18x18mm with a HV Cable RG174 Mounting of SP883a02 long 5 a New Capsule with Preamp holder An improved version with a Pramp Holder made out of PEEK was designed an manufactured 2012 The black PEEK CF30 material was replaced by the natural PEEK because of the unneeded electrical conductivity through the carbon fibres PEEK has better resistivity to radiation than POM but is expensive and difficult to proceed The separating divider bar is omitted in th
18. TP Vin TP2 Vin TP4 Vout P2 E Curret Anz ES TP3 Vin x H iu Dit 27202 in welaufGel ws 2 zuoutsrt xu Lun37T Big W i E 1L EX El GND Power Supply type Basel SP903b shown in photo above for up to 64 preamps at high rate here with SP883c and VPT Alternatives e 6V Adapter from NIM Crate e Wiener mpod control by EPICS via CAN Bus e CAEN 8800 e other Option 10V 2V Operation Not recommended Operation at absolute limits of Opamp with limited temperature range Increasing of output voltage with Trimmer possible but generates more power loss in preamp Change Transformer f e 15VAC 2A to prevent from ripple at high load Desolder or replace Z Diode BZX55C 10V with a 12V 10 type SP883d_Manual_Preamp page 33 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Pulse Processing Signal chain Photodetector VPTT APD Photodetector Gain 50 100 2 5V 500hm 2 5V 500hm 2 5V 500hm 0 5V pC 0 5V pC 0 25V pC or 0 1V pC Shaper peaking time 650ns Tiz250ns Td 2us 650ns Ti 250ns Td 2us 650ns Ti 250ns Td 2us ADC input single ended Struck SIS3302 Struck SIS3302 Struck SIS3302 Spice Simulation A precise Spice model of the LNP Preamp including the shaping filter peaking time 650 ns has been developed Spice is the abbreviation for Simulation program with integrated c
19. also best for noise and stability Ambient light tight protection also from rear side is absolutely necessary If not the tube will get damaged when operated SP883d Manual Preamp page 21 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version 4 Assembling VPT VPTT To achieve maximum flexibility in connecting the different photodetectors and mechanical construction the two PCB s of the preamp are delivered separately and have to be soldered together with four solder joints by the user Several variants are possible Variant 1 VPT soldered via litz wire Variant 2 VPT soldered to Preamp with a PCB distance of 4mm overall length ca 78mm Variant 3 VPT soldered close to Preamp with a PCB distance of 10mm overall length ca 3mm see Photos below Length of Preamp R11375MOD Hamamatsu Tubes 73mm with very carefull handling down to 70mm if distance of PCB s is 8 10mm the glass exhaust is then overlapped by both Preamp PCBs If you choose a 4 mm PCB distance the overall length is then 5mm more lets say around gt 5mm b The Hamamatsu R2148 and the RIE Tetrodes without silicone potting are tubes with a pin socket which allows proper space saving construction f e via a socket or direct soldering to a disc shaped interconnection PCB TER Left comparison with without silicone for RIE VPTT Photo Tomas Held RUB Right VPTT R
20. coating for printed circuit boards Plastik 70 A transparent acrylic resin based transparent insulating coating Protects against normal atmospheric influences Soldering for repair is possible e Over 100 channels up to the year 2010 are in use at different sites institutes under different conditions in beam low temperature Over 200 channels more will be built in at Bochum Proto192 and Uppsala in 201 1 e n the past defects occurred with FET s and Tantalum Capacitors Reliability can dramatically increased through prevention from ESD and other good handling practices Production tests To test production volume of the electronic functions we have built a test adapter with spring contacts because the pramps were built without connectors wired Tests include 1 power supply current both 6V 2 gain calibration of the test instrument chain with pulse 3 noise output with 270pF at input EL 1 gt t iO oj Adapter SP883d01 fo Sey fe ys gt Radiation Hardness Specially in the center of the Forward Endcap radiation is not negligible Tests in Spring 2010 at Mainz Dr Irakli Keshelashvili showed that the Preamp will not be destroyed in a Beam Online Tests with quantisized radiation will be proceeded SP883d_Manual_Preamp page 45 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Addendum Experimental Setu The P
21. consumption oo 47 Magne UC CIOS e C rT 47 Melle recados so ee oca a e a aa aa Roa de aa 48 Energy resolution Comparison of ASIC readout prototype 16 amp LNP readout Proto60 48 RoN OG a 54 be adds Gh 4Ged be eh eC eS URE E deeb TT TIT TT ee ee nee as 49 Go I MMC 49 Overview LNP Preamplifier ChAmp Charge amplifier Familiy Evolution Chart 50 Ine m PeTT CT T P PrPTr Sl Test Sel 9l 9096 uu 22 04 00 bra ae a charge 52 The Prototype SP8839IC U an u nun aan ana RERO a a aa ne a UR ee ae 53 Glossary ADDEeviallOfiS 4 4 2 4406 68469 40 Seba a a an Fd A BO A e ie ee 53 LAAKS daa ad ee ee ad eee a ee 53 TA OK 5 Precautions Electronic circuits can be damaged by Electrostatic Discharge ESD It is strongly recommended that all devices be handled with appropriate precautions Failure to observe proper handling and installation procedures can cause damage ESD damage can range from performance degradation to complete device failure sudden or while operated ESD is produced by walking on floors through friction on isolating surfaces shoes clothes etc Basic methods are not to touch use conductive ESD bags to store and grounding strips when handling the device Concept of the Panda Electromagnetic Calorimeter EMC readout The Low Noise Low Power Charge Preamplifier LNP
22. que Meni P vua Mace OPS mr b Vm Er arg 1 LAAPD per crystal m active area 10 x 10 mm m QE at 420 nm 80 m Gain 50 L NP type preamplifier m ENC 1700e O 25 C B Energy noise level 725 keV 2 Panda EMC Forward Endcap Proto 192 192 crystals red marked part Uni Basel Uni Bochum etc Lichtfaserhalterung 3 V VPT mit Feder a pd T Hr Mountplate Insert Kristalle Alveole 9 http panda wiki gsi de cgi bin view EMC ForwardEndcapEMC SP883d Manual Preamp page 5 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Main tasks challenges e low noise at low power Signal transmission output voltage dynamic range Low overall cost easy operation Energy and time measurement no onboard shaper Max Rate pile up Integration of a low power loss HV bleeder for operation in cooled areas Mechanical integration in limited space with onboard HV Flexible design for different photodetectors APD VPT VPTT Family of LNP preamplifiers oince the APD Version of the preamplifier was developped years ago and many measurements and tests were performed with it refer to the datasheet SP883a02 or the TDR 2008 for specific data for use with APD s The actual version SP883d and the new types of vacuumphotodetectors were developed in 2010 Therefore they are still in test phase Below an overview is shown
23. short glass Proto VPT 750V Hamamatsu Photo Triode R2148MOD short metal shielded Kovar FeNiCo can 224x 30mm Hamamatsu Photo Triode R11375 MOD3 VPT 750V 24x 404 10mm Hamamatsu Photo Tetrode R11375 MOD VPTT 750V D24x 40 10mm Research Institute Electron RIE St Petersburg Photo VPTT 1200V 222x 32 mm Tetrode RIE FEU 189 21mm IHEP MELZ VPT RIE FEU 190 25mm IHEP MELZ VPT CMS e Other Photonis ET Prototype Photo SP883d Glue candidates silicones Dow Corning RTV 3145 Elastosil RT 601 SP883d Manual Preamp page 7 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Photodetectors a Hamamatsu Triode R11375MOD3 K A D GND 750V 500V Dy2 Only for Tetrode Dy1 BOTTOM VIEW gt Hamamatsu Pin numbers new version C Hamamatsu LAAPD S8664 1010 old 811048 new rectangular 4 x Cl ACTIVE AREA Cathode Cu Non magnetic PIN 1 5 0 3 Epoxy F 0 4 Serial number o 7 0 5 o O From center of active area to center of package 0 5 1 d RIE Tetrode VPTT RIE Vskuum Photo Tetrode A C l Phalokaihode DW I 1 Dode 500 Gitteranode 1200 V m GND 0 5kV m 1kV RR Thanks to Michael Leyhe RUB 29 1 2010 VPTT RIE with silico
24. significant impact on the total detector capacitance it must be kept as short as possible The dark current of the VPT is significant lower than the one from the LAAPD 1 nA compared to 50 nA both measured at a room temperature On the other hand the quantum efficiency QE of the VPT is only about 2096 compared to 7096 of the LAAPD Further the internal gain M of the VPT is only around ten which is five times lower than the LAAPD The noise floor of the LNP Preamp at 25 C loaded w ith an input capacitance of 22 pF has a typical equal noise charge ENC of 235 rus This is measured with an ORTEC 450 shaping filter amplifier with a peaking time of 650 ns Because the VPT has almost no dark current the noise is not increased due to the leakage current of that photo detector Assuming 100 photons MeV at the end face of the cooled 25 C PWO II crystal would result in 43 photons MeV on the active area of the VPT This is coming from the fill factor of 40 VPT active area of 268 mm with respect to an end face area of about 625 mm Since the end face not covered by the VPT will be masked by highly reflective material we assume 50 photons MeV on the VPT By applying the QE and the internal gain of the VPT a primary photon with the energy of 1 MeV induces an input charge of 16 aC 100 e to the preamplifier So an ENC of 235 e rms corresponds to an energy noise level of about 2 4 MeVnys This is almost the same energy noise level as achie
25. version pope Photo shows from top to down 1 LV red 6V black GND blue 6V 2 Signal 50 O coax direct to the PCB or via a ITT crimp part 3 HV orange and GND black and optional yellow green Wiring of prototypes for more convenience see below UNI BASEL Note The GND of the Preamps is connected 5OR Coax RG178 with H FL U FL out GND Anode P Dynode 2 Dynode 1 Kathode GND 2010 12 SP883d Manual Preamp page 20 of 55 via the green yellow litz wire to the Power Distribution PCB The shield f e Aluminium tube d 25mm is also connected through the spring Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version 1 Connecting wiring of power supply Because the Hamamatsu Triode Tetrode R11375 MODx is significantly longer than previous versions f e R2148 there is no space for connectors on the PCB Therel ore wires are soldered directly to the PCB For assembling the connectors will be mounted to the free end of the wires to connect to the power supply distribution board and shaper Use a floating output power supply f e laboratory power supply Toellner 8735 SP903b from Basel in some cases via a NIM Crate Adapter or similar The signal output should be wired with a 50 2 coaxial cable f e RG178 The 2 edition of the PCB series includes the additional possibility to solder a RG178
26. 0 8 Shaper VME modules 16ch KVI 3 000 3 LV Power Supplies 1 000 3 HV Systems 64 ch ISEG 180 000 Photodetectors APD VPT VPTT Hamamatsu 150 000 349000 SP883d Manual Preamp page 51 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Test Setup SP903c a A light tight alu shielded Test setup with NIM and CAMAC Electronics and Linux PC is built Operation with LED light pulses and two PMT s as reference and trigger Test Setup SP903c 9 Lab 1 08 LeCroy 821 Discrim I I i I HP3312A Generator I i I Tektronix Oscilloscope TDS I I I Pos HV F 750V I L I I L I L Wiener LeCroy LeCroy LeCroy neg HV i 2 2551 2259B 2249W ca 1kV i Scaler ADC ADC H L I I L L I f L GND Shield 4 PC Linux USB I e i 2011 W Erni L I U CAMAC Bus b Database for test results datasheets etc http jazz physik unibas ch panda c The two PCB s dismounted with 2 54mm SIL connectors for production testing purpose A i a e o f 3 d 5 i Xi hs Photo l Keshelashvili SP883d Manual Preamp page 52 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version The Prototype SP883 c d Built with modified long pream
27. 3d Preliminary Version Mechanics Drawings for Panda EMC Forwar Endcap Proto 192 Bochum Group Crystal amp Alveoles Crystal Design Tapered 11 different shapes PWO crystals Length 200mm front face 20x20 mm2 Foto right Laminated carbon fibre alveole act as housing for this heavy load Silicone Non corrosive Dow Corning 3145 RTV Clear 2 component Dow Corning Sylgard 184 to couple their scintillation detector assemblies Optical coupling http www loqwell com tech servtips optical coupling grease html Dow Corning Q2 3067 General Electric GE G 688 Blue Star Silicones exclusively for Precision Converting Visilox V 788 Rexxon RX 688 Saint Gobain Bicron BC 630 hnlich GE G 688 Nye Lubricants NyoGel OC 459 Boro Technologies Boro 1000 Silicone Solutions Visilox V 788 SS 988 SP883d Manual Preamp page 43 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Test Setup Recommended Nr Testadapter Own built 1pF 500 270pF Metalbox Jj6side Z s J Tektronix TDS784D 109 Research Amplifier 500 Ortec 450 14257 783Rev 13 Float HV Source Calibrator Fluke 341A 15 not SRS PS325 HP 33120A 85 o po In 9 e 9 e E S n gt E ts a gt S ES o Em DE LE NM or am No oN z 35 Er PER nt yr Qn an doy 7 IN lS JI JN de EN Is ro io le 3 JE je E i i i 9
28. 50Q Output impedance 500 Rise Time with input load detector capacitance 22pF ca 15 20ns Feedback time constant 25us Input Load detector capacitance 0 300pF SP883a02 80 500pF Typical noise performance with RIE Tetrode 1100V Ti 250ns Td 2us ca 625e RMs 1mVRMS 25 C with Cd 270pF Ti 250ns Td 2us ca 2500e RMS 25T 235 rms 25 C Operating Temperature 25U 70T Humidity non condensating Dimension without wires 18 x 28 x ca 10mm Weight gt 49 Note Oscilloscope measured value of 1 mV rms is around 625 electrons rms electrons rms uV 1 6 SP883d Manual Preamp page 9 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version General remarks for operation This Preamplifier was designed to work directly with the VPT or VPTT from RIE or Hamamatsu but can also be adopted for other detectors and mechanical designs As a photon energy of 100 MeV corresponds to a pulse peak of only 3 2 mV the subsequent electronics has also to be designed with low noise performance To save space cables are soldered directly onto the PCB The use of an AC coupled device has many advantages as to prevent common mode GND level problems and crosstalk but might also cause problems because the shift of the signal baseline on the trigger branch side at high and fast changing rates To prevent this the signal output is terminated with 500 Th
29. 60 Magnetic fields The magnetic field is not changing abruptly There are no massive connectors and no inductors on the preamp which can cause a high deformation of the field but several components contents a low amount of magnetic materials as f e nickel as well as the vacuum photo detectors Pretests with no effects on the preamp were executed with 1 Tesla Mechanics The mechanics must provide work as e Holder for the VPT VPTT in a way that the pins are not getting no forced e Holder of the preamp and cable e Metal shielding Below Example not suitable for Panda due to lack of space SP883d Manual Preamp page 47 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Results G Tambave XXXVth PANDA Collaboration Meeting 30 Nov 2010 GSI Darmstadt Energy resolution Comparison of ASIC readout prototype 16 amp LNP readout Proto60 20 Gabler Protol6 Novosibrisk Protol6 Gabler Proto60 Novosibrisk Proto60 15 Energy Resolution un 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 Incident Photon Energy GeV At lower energies the energy resolution is worst for Proto 16 i Li E h noise shp 3 3500 Entries 10437 Mean 0 6026 3000 RMS 0 0002157 y ndf 11676 2500 Constant 3858 46 6 Mean 0 6026 0 0000 2000 Sigma 10 0002156 D 0000015 1500 1000 500 0 6015 0 602 0 6025 0 603 0 6035 0 604 0 6045 Channels Nois
30. Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Nr x IN IN Manual Preamplifier SP883d Preliminary user manual datasheet for the low power low noise LNP charge preamplifier for APD amp VPT T readout in Panda EMC proto 192 Author Werner Erni Experimental Particle Physics Group of Prof Dr Bernd Krusche in collaboration with Dr Irakli Keshelashvili Michael Steinacher Universit t Basel CH Universit t Bochum D GSI Darmstadt D KVI Groningen NL Version 0 5 8 is available on http panda wiki gsi de cgi bin view DCS SupportedHardware Revision History Version 0 1 December 23 2010 Werner Erni Version 0 6 4 July 17 2012 Werner Erni Photo Preamp SP883d Round HV divider soldered to Hamamatsu VPT Main Features of low noise low power charge preamplifier model SP883d Low noise high resolution relative to power consumption For Vacuum Photo Triodes VPT Photo Tetrodes VPTT APD Completely analog electronics Single ended AC coupled 50Q positive signal output Integrated low power HV Divider Bleeder Bias for up to 1 5kV Space saving significant less cables 1 instead of 3 Integrated low amp high voltage power supply filter Reduced dimensions length 28mm short stamp format Two separate boards PCB without PCB connectors Low cost with components of the shelf Operation at 25 C radiation and magnetic fields Fast rise time 20ns for energy amp
31. Beijing Bochum Bonn IFIN Bucharest Catania Cracow Dresden Edinburgh Erlangen Ferrara Frankfurt Genova Giessen Glasgow GSI Inst of Physics Helsinki FZ J lich JINR Dubna Katowice Lanzhou LNF Mainz Milano Minsk TU M nchen M nster Northwestern BINP Novosibirsk Pavia Piemonte Orientale IPN Orsay IHEP Protvino PNPI St Petersburg KTH Stockholm Stockholm Dep A Avogadro Torino Dep Fis Sperimentale Torino Torino Politecnico Trieste TSL Uppsala T bingen Uppsala Valencia SINS Warsaw TU Warsaw AAS Wien cl za i tr Barrel 11360 PWO tapered Crystals 11 different shapes 22720 APDs Forward Endcap 3856 PWO Crystals Vacuum Photo Detectors Triode or Tetrode APD s Backward Endcap 592 PWO Crystals APDs SP883d Manual Preamp page 54 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Contact Werner Erni unibas ch SP883d Manual Preamp page 55 of 55 Physics Uni Basel CH 4056 Basel
32. F fast gleich aber die Bias Spanmung liegt h ber C15 100pF statt 47pF Compensation typ 6301 C11 C12 1000V statt 500V Deshalb wurden die HV Filter C s auf IkV ge ndert Die R2 50k statt 10M R s vertragen kurzzeitig h here Spanmmug R3 100k statt 22M F r die neueren LAAPD liest die Bias Spanmung wieder SOV 2m T SP883d Manual Preamp page 30 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Distribution of Power Supplies The distribution of LV and HV can be done vi a PCB Design by Mario Fink Bochum HV HV Crates from ISEG controlled by EPICS via CAN Bus ze E a d Has c DR l E y D E 3 Left Proto60 with HV Right Tests in Mainz Tank with dry nitrogen gas A Vacuum pump B X Y Support C High Voltage Supply D Proto60 E HV for Proto192 APD HV Module ISEG EHS8 210p F 1kV 8mA High Precision VPT T HV Module ISEG EHS8 620p F 2kV 4mA 35 channels for VPT T HV sharing 1 HV among 4 channels and 64 channels for APDs sharing 1HV among 2 channels Control Software is EPICS Bus is CAN Test beam at Bonn is preliminary scheduled end of July 2011 Delivery by the end of June to Bochum 5 HV modules ISEG for VPT T use 8 HV modules ISEG for APD use 2 crates ISEG with CAN Bus for the modules SP883d Manual Preamp page 31 of 55 Physics Uni Basel CH 4056 Basel Basel LNP
33. I I 1 I I I I I I I I I I I I I I l I I I I N Pie Pia aa Bi I Al rimis crm ala E SE hp umm LIU Feria H8 Pi m EE num amm cmo Peg L mew dms om ELO EE Hum may Ula Bars d iu RH ei XEM Bu IRE CER it EEE i uie ro AA ATL TE IO ETC E beah om eel TIERE LET a US e Me LLE EA RE Fr w oa NOI RE Z Mad immi ram lag numm be mois eo CEN DIOS RH LES did TURNO ir aus nmm Pa Unipslar Taie Pulse Cumt b 55 pa dan an ou E ud El AAA 7 ams Wa um ung nori Po nO E o0 mime Baar rx maar uer im E Lean aia a eel a A a lium Er in Sin q sd Hulk Apr me la am pre Gee S Gm Te nhan d ore me mmh Lo nie um mem ua hep xs HE Pom imar ire helai cmm sc nume be lE ja imum Ee had pnh Ear come nimim e chua Ni Cie numm meum E LITE Lom lidia Jo meg ima ETET Eb DERA m Uh Colom Fa nn ge gno E CEE mm am mob L20 TI raw ri us derma ku cmo gp an A arn am rd karm risp CB Gui oim IE meen Snbumcaeroyamg foe jam Emih O Hber a ri Le da a me sal ma Mm eee e rr cr esas reia dd EE A T ois ip io a gradum D cem iam 106 a or mz E TROC Fu Dum zi z UY iim cina amc me m air mara Lu rua lm JE ga nh um PEL ha m me P me hnjns sb mam Rag etm TT JL tg vui mam am ll a TE B Kleinen SP883d Manual Preamp page 28 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version 6
34. IE bare without silicone 2 unused pins cutted Below Universit t Bochum with Hamamatsu VPT T SP883d_Manual_Preamp page 22 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version SP883d Manual Preamp page 23 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version 4 a Assembling VPT VPTT new Version with round HV New features to improve manufacturing and stability of Hamamatsu tubes e Round HV PCB for Hamamatsu VPT or VPTT RIE has different Pin configuration e alternative HV Connector Molex Spox coded locked for HV connection cut one edge Abrade 1mm of PCB from Preamplifier PCB carefully or mount the PCB transversal Solder in wires and Preamp PCB justified into the round HV PCB Solder HV PCB to the VPT T Glue PCB with small amount of non corrosive silicone as Dow Corning 3145 RTV o the VPT T 60mm shrinking tube 0224 mm onto the tube with HV PCB or kapton tape to isolate the HV Wrap around 78mm self adhesive Alu foil sized 50mm or even better more f e Tesa 50575 SUCRE A A Example see also http www bonner rice edu hzhou up_pvpd construction html SP883d_Manual_Preamp page 24 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version 5 Adapter
35. KB SMB Restos 59 Voom Nasa 00 ihe 2 Nae D us Example circuit generated from www analog com diffampcalculator Ortec applicaton note passive Creating a Differential Output to Cancel Environmental Noise When the coaxial cable connecting the preamplifier output to the Small Metal Box shaping amplifier input is long and the cable runs through an tristem electrically noisy environment it is advantageous to employ differential short 15 cm Cable signal transmission Several amplifiers Models 450 671 672 973 ee CN eee and 973U offer differential inputs for this purpose A few preamplifiers To Amplifier include differential outputs to accommodate this function If the mee eee preamplifier does not provide differential outputs the box depicted in Reference Figure 7 can be used to create a differential output All the components shown in Figure 7 are mounted in a small metal box located close to the preamplifier Care must be exercisedto Fig 7 An Add On Box to Convert a Single Preamplifier Output to a ensure low impedance grounds The input on the left side of the box is Differential Output connected to the normal preamplifier signal output with a coaxial cable that is as short as possible This short cable must provide a low impedance path from the preamplifier ground to the metal box The center conductor of this short cable transmits the normal preamplifier output signal through the box to the no
36. Model Type No Photodetector SP883a APD 10x10mm 500V APD single channel family 18x48mm PCB 0 8mm TE VPT short glass ar With round shaped filter PT A soldered to tube SP883a02 is 500V compensation for up to 500pF With 1000V capacitors Bias APD ca 650V compensation for up to 500pF Low Gain Low Bias HV filter resistor 150k 100pF compensat SP883b APD 10x10mm 500V quad channel Proto60 46x46mm SP883cC VPT metal 1000V without onboard HV divider PCB 4 Layer 1 6mm Hamamatsu SP883 c d PL 1500V Prototyp Umbau von SP883c auf Funktion v d SP883d 1500V Combi family APD VPT VPTT stamp format 2 PCB 18x28mm with onboard HV Divider Hamamatsu Hamamatsu 100pF Compensation value is implemented designed for VPT T This may cause to a little slower rise time but better stability specially at lower temperature Also used for LowGain APD SP883a03 Standard value for APD with 6V is 47pF for 8V 2V 100pF Note type number key Example SP883d01 APD SP Schematic Plan 883 Projectnumber Electronics Lab Physics Basel for the Panda EMC Preamp d Model Type 01 Revision Version 1 _APD variante adaption SP883d_Manual_Preamp page 6 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version For use with Photodetectors f e for following devices Moel Tpe Notes Hamamatsu Photo Triode R2148
37. VPT T 8 APD readout model SP883d Preliminary Version Schematic diagram SP883d for VPT VPTT ali Rod HV RlaR1b 4R2a ROU R3a 4R3b Low Power HV Divider VPTT RIE 3M34MTH10M 10M H10M 10M 48M 200V 500V 500W25uAy 30mW bei 1000V 20mW VPTT Ham 10 0M 10M 10M 10M 10M 550M 150V 300V 300V 15u4 12mW Unipolar Positive Pulse Output 0 5 V pC 4 500hm VET Ham 10M 0M 0M 0M 10M 10M 30M 250V 500V 25u4 20m W APD Hamamatsa R1 R2 R3 open no divider only filter Rl2a b R13a b Hamamatsu Trig Bias Voltage pi Input max 1500V mea 2550Rx22uF 2 2ms DVM mit Ri 10M Messfebler 80 I I I I I i E Unterschwingen Verschiebung des Pulses ins negative bei i L r hober Rate geringer Baseline Shi ft I D Note EV Filter t MN lower R lower voltage drop come 5 1 6 y k Higher C 2C5 parallel in 3D T Alla T Gack i0w soov R12 5 I nl 417 1500V xnl 33R momentary l 5kV until amp 3 gr C ci GD 6V I capacitors are charged Lotur A I specified for resistors 47uE 10V Tantal C4 _ I VIA T Rs m H VPTT Tetrode RIE a 271500V37R Protection 153 100uF 10M 500V 10M 500V Lig13a ee r D AX 1 VEIT ca 10 20pF max 1200V i I 1 I Test Point rate 10M S00V A P AR A irre RA u 3 H ATO j Dl gt 3 ADS A LAR RO BASAL
38. a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Please note that for a constant internal APD gain M the APD voltages must be decreased if you decrease the temperature This is due to the temperature dependence of the gain VS reverse voltage of the APD see the graph on page 2 on the attached S8664 APD data sheet For further details contact Andrea Wilms For the APDs we have measured the reverse voltage had to be decreased about 1096 to preserve the internal gain of M 50 between 25 C to 25 C This was done by using a light pulser system If you have a light pulser system you can easily adjust the APD reverse HVs at 25 C to get the same signals from the preamplifiers as you have measured before at room temperature n HV Supply CAN HV Control Does not work properly with GAN ta USB Interface somm M n x m lm moe c ss c mul nomo e i rum PE E CO PE Meu eof a em o cmm antral Software for tests under Windows OPC fram manufacturer under Linux Bernd Lewandowski abVIEW Slow Control EPICS 2010 SP883d_Manual_Preamp page 32 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version LV 6V or 8 2V e Operation with 8 2V limits the rate more than with 6V operation e Built in Basel dual DC output Low noise linear regulated e Floating output
39. a gsi de http panda wiki gsi de cgi bin view SPC WebHome http forum gsi de Talks http www panda gsi de framework meetings php detectors EMC Thanks to Fritz Herbert Heinsius Thomas Held et al Ruhr Universit t Bochum D Andrea Wilms GSI Herbert L hner Myroslav Kavatsyuk Frans Schreuder et al KVI Groningen NL This work is supported by Schweizerischer Nationalfonds Swiss NATIONAL SCIENCE FOUNDATION SP883d Manual Preamp page 53 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version FAR Facility for Antiproton and lon Research Figure GSI Darmstadt Germany with FAIR project RE 1 BE ll m 19 _ Produktion seltener Isotope Super FRS Produktion von Antiprotonen Plasmaphysik Atomphysik FLAIR existierende Anlage 9 neue Anlage O Experimente Figure Artistic view of the PANDA detector and collaboration groups Target Spectrometer Forward Spectrometer a Muon Detectors T gt LS wd p Forward RICH in _ pm Superconducting Solenoid Electromagnetic Calori ters oa l DIRC GEM yu a Kent Tee i Mare Muon Hadron ID w P Micro Vertex Detector So l ES Austria Belarus China Finland France Germany Italy Poland Romania Russia Spain Sweden Switzerland U K U S A Basel
40. al AC voltage gain of 14 for the J FET input stage The gate of the J FET is protected against over voltages by two low leakage silicon diodes of the type BAS45AL The input stage is followed by a broadband 300 MHz fast 2 000 V us and low power 1 mA current feedback operational amplifier of the type AD8011AR from the company Analog Devices With its typical input voltage noise density of only 2 nV sqrt Hz at 10 kHz this amplifier suits well for such a low noise design The proper frequency compensation is performed by the capacitor C13 100 pF in combination with R2 10 Ohm this leads to high frequency feedback to the inverting input of the operational amplifier Overshoot and ringing can be efficiently suppressed and this compensation also prevents from oscillations when no VPT is connected The output of the operational amplifier is DC coupled via the feedback network 1 pF 25 Meg Ohm to gate of the J FET In parallel the output is AC coupled via a 1 uF capacitor and a 47 Ohm series resistor to the output of the LNP Preamp Therefore the output voltage is divided by a factor of two if it is terminated with 50 Ohm With a symmetrical supply voltage of 6 V the output voltage can swing symmetrically between the positive and negative supply when high continuous event rates at high energies occurs The LNP Preamp draws a typical quiescent current of 6 3 mA from the 6 V supply and 1 2 mA from the 6 V supply this leads to a total power cons
41. ale SMD Harwin Datamate L Tek f e Farnell 177 6199 177 3791 Molex Series 55932 shrouded header Part No 0559320810 SP883d Manual Preamp page 29 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Version Low Gain APD for Proto192 2012 SP883a03 is based on the the same PCB as Version SP883a02 but with some different components to reach lower gain 2 5 and lower Filter resistance Bias HV dependency for Proto192 Filter H2 is now 50kOhm instead of 10MOhm and R3 is now 100kOhm instead of 22MOhm Gain C13 is now 2 7pF instead of 1pF R11 is now 0 Ohm instead of 15MOhm Compensation C15 is now 100pF instead of 47pF GD Positive Pulse Output ev 100nF parallel to shaping ampli ier ADC Y Lemo 00 ci eya d zu A 47R 0 25W 1 Taa 25 500hm RS 23V y GND GND Power Supply Ra 45mW Version SP883a02 BESAR fur 270pF 108 f r 2pF APD 33 470R rauscht weniger als 200 300R SV weniger pile up als mit 8 2V 47pF Kompensation uber OP bringt Stabilit t Low noise Einganzsschutzdioden BAS45A C14 neu 22uF ISR 1206 statt luF besseres High Rate Verlniten teilweise wurde 22uF YSU verwendet schlechte Elektrontkiabor 2 17 Temperaturstabilit t Version SP883203 lower gaiw HV Filter C13 2 7pF statt 1 pF gain F r ltere rechteckige LAAPD bleibt die Kapazit t R11 0 statt 15M time constant 300p
42. am C2 Pk Pk 16 72mV v M5 00us Ch2 28 2mV 21 Aug 2007 14 03 45 with Ortec450 Ti 250ns Td 2us Q pC xU mVrms 10 1 6E 19 Noise electrons z B Noise in mV Std Dev x 1000 1 6 electrons Measurements taken with approx peaking time of 650ns Ti 250ns Td 2us Similar test results are taken with peak sensing ADC see test setup SP903c below SP883d Manual Preamp page 13 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Example Noise measured with shaper and oscilloscope E D g E d i E 4 I n TEWUWWWWVT gt pB f Source of the noise Tek Run 5 00MS s 2E JA 14 12kHz ce O Run 5 00MS s a Run 5 00MS s sample P R E F EMEN e je 13 85kHz Ja 14 12kH2 ff JA 14 12kHz m 13 85kHz amp 13 85kHz NICO osp Tri EREEUER m 2004W i HsStdDev HsStdDev i a i S00JV 2 74mv er WE 1 00mv Mi0 0us Ch2 J 12 1mV 15 jul 2011 pee Looma Mt 04s Ch2 12 1 15 ul 2011 Co BE Soom Wes Ch2 7 24 1mV 15Jul2011 12 15 51 12 16 40 12 18 34 Left oscilloscope input 0 2mV rms Middle measurement setup 0 5mV rms Right with amplifier 270pF 2 7mV rms Method SP883d Manual Preamp page 14 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for
43. an integration auf 4 i i i i i J X R Ver dtr LAAPD time constant Tin 250 ns and a differentiation time constant Taiff 2 us 22 pF ad 270pF which corresponds to a peaking time of 650 ns TOUS MENA Z Physics Basel i Rise Time Timing Information Na s Ti E Tek Run 4 00GS s ET Sample ime vs Energy umm o3 MAA Hs StdDev 0v PA Time preamp TM A A Peas Be i 4 emo a Precise time ES SR cronica information Ji 13 56ns Energy enig 15 14 47 NEA 5 XK e ES m A Single Pulse Response of LNP Preamp m Rise time o f LNP Preamp dt pe nn een ee ee ini U Measurement with LED pulser 470 nm Measurement with LED pulser 470 nm LeCroy LeCroy ES 1 VPT Hamamatsu VPT Hamamatsu I gt Rise time 19 S constant 25 us E Rise fime ns S Vor 750 V Vo 750 V Q Vyy 200 V S Vpy 200 V A N N Qin M P C Qin 2 P C vs E P2 av P3 P4 P5 P6 PT ae 18 2 wey gt 20 us div ws E k gt 50 ns div May 2008 Michael Steinacher Physics Basel 26 May 2008 Michael Steinacher Physics Basel 27 SP883d_Manual_Preamp page 37 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Simulation NP Preamp T Filter Trans PSpice A D Trans dat active E edd xd Bele Edt Yew Smuanoo race Pot Took Window Bep RE del xi ar ll ee os LNP_Preamo_T_F
44. ctor needs his very own typical divider circuit which is placed on one of the two boards As tradeoff this results in slightly more noise A precise power on point HV generation onboard active base is not foreseen due to additional heat generation and the magnetic fields at that point The use of unshielded magnetic components as inductors for power conversion and filtering is problematic The leave out of connectors reduces material volume costs and weight and increases reliability The preamp is connected to the next signal chain stage either a shaper or a distribution panel via short wires cables PCB and the connection to the photodetectors is also possible with short distance The preamplifier is made of commercial standard low cost components of the shelf An adapted version for use with APD s is also available The appropriate HV circuit filter which works also as an interconnection to the APD s is designed for two preamps crystal of either type SP883d 18x28mm or SP883a02 18x48mm This version has reduced series filter resistance to reduce the voltage drop at high rates SP883d Manual Preamp page 4 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Panda EMC Barrel Proto60 Picture Tobias Eissner Uni Basel IPN Orsay Uni Giessen etc m 4 crystals packed together m Wrapped with reflector foil ANA 502 0 tros WS ir uc
45. de Power Supply VME Distance shielding crates Digital electronics PC Noise exceeded J Increase shaping time tradeoff pile up Ca 1kHzroling oo Use Struck VME ADC CE y EEE EEE multiple separate HV Power supplies use 1HV with HV Divider Bleeder circuit WA Spratzen Improve HV Isolation cleaning PCB cables Spratzen Afterpulses duration 20 Luminous reactions of electrodes due Blanking if systematic time correlated 100ns to electron bombardment Afterpulses 0 1 10us lonization of residual gas traces Blanking if systematic time correlated Coverlighttight 1 O Firework of pulses oo Light leak from ambient 2 Cover light tight display shaper use histogram mode scope for rms noise Warmup Unlineaity Add capacitortodivider Microphony Ceramic capacitors changes volume Coupling via PCB during voltage changes Conductive packaging don t touch Ambient A0 O Temperature J Cooling for noise reduction don t touch preamp amp photodetector Spontaneous avalanche OOOO Pp contamination 00000 G O Comparing noise measurement results To get comparable noise measurement results take care of following points e Measure V rms if Vpp on oscilloscope divide by 9 standard deviation Photodetector Capacity and gain Crystal Light yield wrapping
46. e Level 4 Stage Shaper with LED light pulser Noise level 1 1 mV Sigma 5V 1 1mV SP883d Manual Preamp page 48 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version References Glenn F Knoll Radiation detection and measurement 4 Auflage 2010 E Kowalski Nuclear Electronics Springer Verlag p 106ff 163 W R Leo Techniques for Nuclear and Particle Physics Panda EMC Technical Design Report Oct 2008 http www panda gsi de framework det iframe php section Calorimetry 2008 Technical Design Report GSI Panda ECAL electronics chapter 6 3 to 6 7 and 6 9 2 2008 Technical Design Report GSI Panda ECAL for photodetectors chapter 5 Myroslav Kavatsyuk et al Feb 9 2011 Performance of the prototype of the electromagnetic calorimeter for Panda Proto60 accepted Ms Ref No NIMA D 11 00181R1 Nuclear Inst and Methods in Physics Research A It will appear on ScienceDirect 2005 Technical Report GSI Panda ECAL p 203 207 2007 IEEE Transactions on Nuclear Science Performance of PWO II Prototype Arrays for the EMC of PANDA Options Noise and power consumption is a trade off Optimizations are possible in both directions Noise and pulse rate decay time is a trade off Optimizations are possible in both directions Noise and shaping time is a trade off Optimizations are possible in both directions 1 To increase
47. e and therefore influence to the APD Gain and crystal temperature The resistors are now 3x 1M 150V total of 450V in a 0805 case because of lack of space for the 2x 500V resistors in the 1206 case The reduced series filter resistance to reduce the bias voltage drop at high rates is partly compensated by a higher capacitor 15nF 500V in 1206 case instead of 4 7nF Additional capacitors on the external PCB might be usefull to keep low noise performance SP883a02 SP883a03 SP883d_APD HV Filter 32 MQ 4 7nF 150kQ 4 7nF 3 MQ 15nF Adapter Filter on Preamp not Filter on Preamp Filter on Adapter Adapter not Adapter 100pF 100pF Detailed View of SP883d APD Note HV Filter lower R lower voltage drop Higher C 2C s parallel in 3D un ach Bias Voltage S2 Input mas 5001 ET SPHBd APD 15n 500V 3cR GDA 15n 500V X7R GND 1 2 p S 4 _ o ae Zn S00VTR H 1mF 600V X7R 1206 1 AVX 1206CC153KATIA Famell 130 1826 2 15mF 500V X7R 1206 low cost 3 Kemet C1206C153KCRACTU Famell 170 2131 4 a 4TnF 500V X7R 1210 Kemet C1210C473KCRACTU Famell 170 2144 ifi os LO Preampliiier 1 and 2 SP883d_Manual_Preamp page 27 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Schematic Diagram for APD SP883d_APD SP883d Horas laur m lar I I I I Hemmm ml AT U t ie I I l I
48. e latest version The depth of the APD bed is slightly smaller to allow the APD to make full contact to the crystal 9 Photos black PEEK CF30 Prototypes not used with modification and isolation natural PEEK latest version SP883d Manual Preamp page 25 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Operating Temperature The lower the temperature typ 25 the lower t he noise of the system Please note that for a constant internal APD gain M the APD voltages must be decreased while decreasing the temperature This is due to the temperature dependence of the gain vs reverse voltage of the APD see the graph of the APD data sheet Each APD has to be controlled individually Soldering the APD Solder the APD with high care e Short time heating e Solder the APD with leaded e ESD Protection a LL Par for Proto192 r SP883d_Manual_Preamp page 26 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Filter and decoupling The APD bias voltage 1s low pass LP filtered by a 10 Meg Ohm resistor and a 4 7 nF high voltage HV capacitor which results in a cut off frequency of 3 4 Hz After this LP filter the bias voltage is fed via a 22 Meg Ohm resistor to the cathode of the APD the anode of the APD is wired to ground The ga
49. e transmission line PCB shielded flat or coaxial cable and the input of the following shaping amplifier must have also 50 impedance The output signal is about 0 5V pC when terminated with 502 1V pC unterminated The peak output is an optimised voltage for ADC Inputs 2V The Preamp has one single ended output and is therefore optimized for ADC s with 2 5V Inputs f e Wiener Struck CAEN etc The signal must be measured relative to its proper ground as it is widely used in critical signal processing Baseline restoring with shaper Ref E Kowalski Nuclear Electronics Springer Verlag p 106ff 163 Prevent the preamp from electrostatic discharge ESD specially if the input is open no VPT Do not touch the boards because of creepage currents through salts from hands Floating power supply 6V f e from a NIM Chassis the Basel model SP903b or a laboratory power supply alternatively 5V Floating HV low noise power supply often a linear regulated HV power supply as the Fluke 341A The filter circuit of the preamplifier is designed for positive HV Max voltage is 1500VDC The voltage divider is placed on the preamplifier with only one HV wire to save space and thermal conductivity The power consumption of the voltage divider is significantly lower than the original circuits recommended from manufacturers to make an on board divider possible for cooled experiments The power consumption of the voltage divider is in c
50. ed eee ed eee ede eee ed s e 1 udin WO MACC MET NE DE MENO A A E q A AA A A eee ay A O a Pu E E rei D 1 E 1 1 1 1 A 5 3 1 1 1 D 1 p M E T T T y T T ra r 1 RA 1 1 i Mae e Ww ee e 1 L 1 1 1 Lemo 00 opt QD dead A A es EA ANA d M iH iH 300ns Positive Pulse Output to shaping amplifier ADC U Daten Orcad PSpice Gruppe_Krusche PANDA EMC Q Preamp Q Pream y i a p s N q Blei Y SE o m E amp T H m t E n a et 8 v E o P dir y r cu B LI E 5 a iA 8 a am w i e on 7 s EN yl z can n As E a o n m a iT Ag 3 a 5 E at ho a gt ja I E IS s lo A N zo a M a gt lo LE a e B o pH 1 Es H A v N mA 1 Eo H Wu E E E 8 E a mE o 2 o o o gt n o i gt iD iD m o cl ol al ri I 8 e A a QE pel Z Id y 3 i Im al S M S D B amp old i d BENE i 8 zs i i ja o i EIS 3 ud E MER F Ec 1 8 E 5 i a sl 58 i 588 E Bip 2538 omg for ve EH H 3 i Bee 8 o 88 i 5 gt QST Tun 3 alo Eom G N SE 158 i td os AMV P xl i Be gs A 7 PE eS S c x i 22 i g 34 i ni 5 A 4 Ss i SON la 8 i ES zu PL H 3 i sy s di A SU gt 3 ik g a W g amp e j s FR Bom P tb i l
51. ee 34 SII ITINERE AA EA ee ed AI de A AAA E IS AS A 34 SPICE SIMI TON ds a D Medes a de Gn ge Nak ars de c 34 O ee 35 Dynami Range sitas pi e ea c tees bod qu wear qid in UE S ood o Ea 35 lei he Sree eee ee Ce Bt ei a ee aon Hee EE Uae lea Shore Rh Os oe 35 PIES a A cae ahah ea ae Ra E DS deck eee Wt do sa CREDE 35 SIGMA tO NOIE Tao 2 di trei uh Ye I RR xd de t deris de di ok ye 36 Noise vs Cooling vs detector capacitance ee eee eee eee 37 rises Time Timing Iptermalloli s s cs sse Sese ERE ALA A ES CN Shape tag idis a Lau ur EU dd LN du esr rabat a ds re Apol 38 RAO P 38 AID Gaal dst SS doit atis Lars buds de abut E bo adea dod 41 Matching single ended to differential signal conversion 41 NECHANIES ind 43 GIY STAI S AIVBOIB S x35 ut dod s Ae It ai RUN CR RUN CERT E AUR IURE A A 43 Test Setup Recommended u 44 SP883d Manual Preamp page 2 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version APP o 45 N esos ena aa io 45 PrOGUCUON IESS atar teca ica dado a Ato rer here dd ade 45 Radiation Hardness seis 6392 3969 2 9 3 9 3 9 1 9 100 nes a eB Se ee 45 Addendulit AAA PA e xv RE dI MEINES EIE RU R ssxxE ias ap CN EE rU UN EI UNE 46 zdeiti iike joP rrT 46 Beam TESIS arado deren ena de e o a a e a a A 47 Distribution of Power
52. er shaping SP883d_Manual_Preamp page 41 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version LOW PASS DIFFERENTIAL FILTER Similar to an op amp various types of active filters can be created with the AD8132 These can have single ended inputs and differential outputs that can provide an antialias function when driving a differential ADC 2 15kOQ 1 8V TO 45V Vs O N 0 4x NC IN 0 8x 01035075 AD8475 Figure 77 1 MHz 3 Pole Differential Output ME Nos our Low Pass Multiple Feedback Filter I2 m 74 TO 18V Figure 77 is a schematic of a low pass multiple feedback filter The active section contains two poles and an additional pole Av is added at the output The filter was designed to have a 3 dB frequency of 1 MHz Vi or i Opamps LT6202 LT6203 Diff Amps LTC1992 LT1994 pensi ici ii NET a x T webrmedPcemegans I deo B tn retratados paprat tet OUASCT SOT ima dr o Po 98 Miisa Saiten Ersa Schritte Ay Mad H a Psor det V gt osteingar ril Posteingang Borde w An Posteingang a W 1 bis 17 von 17 Nachrichten Einstellungd Auswahl 4 q Abmeidan Laschen Wiaderheestatian wel Nr d Zeige gakschte Endgcitig loschan Gr e 2 KB 4 KB 230 KB SKB 3 KB 10 KB 514 KR 8 KB N cosa KB 2 K6 476 KB 130
53. er minimized SP883d Manual Preamp page 17 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Circuit description APD preamp SP883a02 The circuit diagram of the LNP Preamp is shown in Figure 3 It is the same circuit for the single channel and the Quad LNP Preamp except that for the quad version the voltage reference U2 and its supply R10 C6 is common for all the four channels The AC coupled input stage consists of a low noise J FET of the type BF862 from the company NXP Semiconductors former Philips This industrial standard J FET is often used in preamplifiers of car radio receivers It is specified with a typical input voltage noise density of 0 8 nV sqrt Hz at 100 kHz and at room temperature The J FET input capacitance is 10 pF and the forward transductance is typically 30 mS at a drain source current Ips of 5 mA Along with the 470 Ohm AC dominant drain resistor this transductance results in a typical AC voltage gain of 14 for the J FET input stage The gate of the J FET is protected against over voltages by two low leakage silicon diodes of the type BAS45AL The input stage is followed by a broadband 300 MHz fast 2 000 V us and low power 1 mA current feedback operational amplifier of the type AD8011AR from the company Analog Devices With its typical input voltage noise density of only 2 nV sqrt Hz at 10 kHz this amplifier suits well f
54. escent current of 6 3 mA from the 6 V supply and 1 2 mA from the 6 V supply this leads to a total power consumption of only 45 mW Operating with an asymmetric supply voltage of 8V and 2V gives more restrictions at high continuous event rates but is principally possible it results in a little higher power consumption of 50 mW To set the 5 mA operating point of drain source current through the J FET a gate voltage in a range of 0 2 V to 0 6 V typically 0 3V depending on the DC characteristics of the individual J FET has to be applied This negative DC voltage is fed from the output of the operational amplifier via the 25 Meg Ohm resistor to the gate of the J FET The operating point Ips 5 mA is fixed by the well filtered DC voltage applied to the inverting input of the operational amplifier This set point voltage 1s obtained by subtracting 2 5 V from the positive supply voltage 6 V by using a 2 5 V reference diode So the same voltage drop of 2 5V must also be present over the total drain resistor of 503 Ohm 470 Ohm 33 Ohm this results in a stabilized DC drain current of 5 mA SP883d Manual Preamp page 18 of 55 Physics Uni Basel CH 4056 Basel The Lower Gain with 2 7pF and 10MO Feedback needs a different compensation Instead of 47pF in SP883a02 Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version 100pF is used to prevent oscillations SP883a03 APD Pramp LowGain PSp
55. g Alu box which is grounded by the output of the LNP preamp e g by a BNC wall feed trough For the photodetector HV bias voltage use a low noise floating supply use a shielded SHV or MHV cable to connect the bias voltage to the metallic box via SHV MHV feed through this interconnects the ground of the bias supply and the output of the LNP preamp Use a low noise linear regulated and floating power supply for the LV supply of the LNP preamp 6 V or 8 V 2 V The reference ground of the metallic box is coming via the 50 Ohm BNC cable connecting the LNP preamp output to the oscilloscope DAQ The oscilloscope DAQ has to be connected to earth ground In general it is very important that only one ground oscilloscope DAQ is connected to the metallic box otherwise nasty ground loops will interfere with the very sensitive signals Noise Datasheet SP883a01 To reach the required low detection threshold of only several MeV the noise performance of the preamplifier is crucial The VPTs have an outside diameter of 25 mm and a typical photocathode with a diameter of 18 5 mm resulting in an active area of circa 268 mm Compared to the active area of the LAAPD 100 mm this is an increase of a factor 2 7 The VPT anode capacitance is around 22 pF which is more than ten times lower than the capacitance of the LAAPD this results in a much lower noise from the LNP Preamp Thus the shielded cable between the VPT and the LNP Preamp has a
56. gnal with 15GeV is expected around 1V depending on Gain of photodetectors Dynamic Range The lower end of the dynamic range of the preamp photodetector system is given by the noise floor of the readout chain The upper end is limited by the positive power supply voltage of the preamp In areas where much light is arriving at high energies the gain of the photodetectors can be reduced The gain of the photodetector is varied simply by the bias supply voltage via slow control system This way different gains for different regions of the EMC can be achieved simply by calibration and controlled by the slow control as wished Where the gain of the photodetector itself should not be reduced the gain oft he preamp can be reduced by modifying the component values in the circuit To increase the output voltage range operation with 8V 2V max 10V 2V is possible Rate Quiet high continous rates see plot below are possible especially at low energies low charge but is always limited by pile up To cope with the expected event rates in the barrel of maximum 100 kHz per crystal the LNP Preamp has a concerted feedback time constant of 25 us This feedback time constant is a trade off between noise performance and pile up problematic For a single pulse or very low rates the LNP Preamp accepts an input charge of up to 4 pC for a continuous event rate of 100 kHz an input charge of up to 8 pC is allowed This discrepancy is due to the follow
57. ice Simulation T 1 31 1 o Ter T m rer T T E X ab ow 3 1 BE EA Ea y EED WER E XC EA pa iD Lu Jd Lb 4 LE j L 4 I 4 r 4 FE 4 L 4 I L 4 d b 4 b 4 Il 4 t 4 5 es al yt A i 1 CH pP Y d od 2 wa d 3 GI EA E 1 Lo od d Er ET 1 A RT E o n e aaas go pesos letal eee ass ee pnl pool ede a ae a a PE a a POE SIE MY i Y d PX 1 DE EA PA VOX v3 EN c Ares de ee Eee a A ee beet gt v y qud 2 1 r1 EX EY Y ETA IES Y E ni H 1 D 1 1 D I 1 1 Et NK D 1 D 1 i 1 Id sc ace eats ar tes bec SEE TI ea iy pl ia ote bey ea ot a ea cl ed pe Gets ee oa el et aa m bod 1 1 b D 1 ES 1 tt c 1 Www 1 1 Y W 5 Du E 4 oo o 8 4 f od 1 QE i 1 ES a Xx St 1 By D R 1 D 1 s y Y tot v 1 1 1 ET 1 i 1 1701 x B i 1 1 1 DA 1 i i Mi E E Haare Ho 4 4 p 4 r 4 p 4 B 1 B t 4 t 4 D E GTA 1 3 C kA EELA di bod Cw d A Aedo MEE MI E a a a aa a an ann nn RH HH b 1 toe i 19 Yi dc el MS NS NECI Ls T Ed inan cce Cael Es m Ele Sm qi den qe ete e i er S SES SES N nn Motore eap nee pc atak dana 1 Fou p 1 i 4 a qe M y duo a og a 6 m m o P u pp E 1 n L pL qc P E Y Es Cody tot 1 d 1 Kk d mo ox d i E ew ey b 8 A 1 Y i Jod Ug d c I E DN gt d epp ds do ra ep ed eds ord ep ead ea a oe a e amp MI MC GS Mae 1 33 53 MA CS mE Kil A Noe fe A o O AS A ee UTA 1 1 W 3 Y dp EM I oj EN i Li 585 NN TAG Y 1 15 4 1 a ee M EET SIE EE as ped ds e
58. ing reason A single output pulse starts from zero output voltage and is limited by the positive supply voltage 6V of the LNP Preamp At high continuous event rates the output pulses will swing between the negative 6V and the positive 6V supply voltage therefore the maximum input charge is doubled If a 100 kHz event rate is applied abruptly burst to the LNP Preamp it takes around one second until a continuous input charge of up to 8 pC is allowed During that transition period a maximum input charge of 1 pC can be handled With this charge restriction the output voltage of the preamplifier stays always in the linear range and is never limited from the power supply voltages Nevertheless the electronics after the preamplifier has to perform a good base line correction because at higher rates it is likely that one pulse sits on the trailing edge of the previous one The operation with power supply voltages of 8 2V limits the rate more than with 6V operation Pile up High energy at high rate leads to pile up The long tail of the LNP Preamp output is determined by the feedback network 1 pF 25 MegOhm of the charge preamplifier The resulting 25 us are a compromise between low noise performance and high rate capability pile up In principle the time constant can be reduced but results in more noise at least if you use a shaping time of around 700 ns The shaper after the preamplifier can reduce this fall time without any prob
59. ion over the length of the crystals The LNP Preamp has a quiescent power consumption of 45 mW The power dissipation is dependent on the event rate and the photon energy at very high rates combined with the maximum photon energy the power consumption is increased up to 90 mW SP883d Manual Preamp page 3 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Introduction This LNP Preamplifier was built for applications where low noise and low power consumption is essential as specially for the PbWO crystal read out of Panda Calorimeter at GSI Darmstadt Preamps with lower noise are available on the market but then with higher power consumption The model SP883d is the latest version of a family of preamps originally designed for APD with a capacitiy of up to 500pF f e two paralleled Hamamatsu S8664 1010 or 811048 The output is a positive low noise single ended 50Q signal useable for energy and timing measurement Therefore no shaping is made on board this must be done externally The shaping time for energy measurement defines then the noise While the signal noise ratio with VPT is comparable to those with APD the absolute signal and noise level is much lower and therefore the sensitivity is higher and all activity to prevent from noise must be even better The influence of the noise from the preamplifier is proportionally higher in relativity to the vac
60. ion peeliminary R10 18k f r 200uA an 6V y 45 300mcd I High energy high rate leads to pile up E f r Kurzschlusssicherheit Speisungsseriewiderst nde anpassen 5 Sloan L3B51G Very good shielding must be provided to Different shaping time se Kein Kathodenschutzwiderstand n tig da 40MOhm ar Dynode M SP809 f ngre low noise operation via case higher voltage drop on HV Filter A kurze Leitung OP out zu 47R weniger Schwingneigung bei Kapaz Last electr tex circuit i mounting holes cable shields Supply GND Option k rzere Feedback time constant z B 2 lt 4M ca_ Mus Fesdback C h here Kapazit tzuiedriger Gain i P I besser f r Bursts Filter auf ein HV Filter in diesem Zweig wurde bewusst verzichtet VPT T typ value 22pF gleich f r continous rate 5 Elektroniklabor 2 17 1 Sensitivity IV into IpF is 1pC which N SL Fal ru url v me generates IV max ca 5V after _NIZNIZ O rJ 82 _ LA O A and 0 5V pCia 5008 XX Ny CI 9020 DASE L max ca 2 5V NIZNIZ gt j I Noise Measurements Q pC xU m Vins 10 1 6E 19 Noise Elektronen n N TT Revison apply capacitor to input z B Noise in mV Std Dev x 1000 1 6 Elektronen IN p i of l e 270pF shaper 250ns 2us results in noise of around 3mVrms UNI 3 T close shielding box RASEI i Differences between the versions of SP883d PS rectangular VPT VPTT po R a Rtb R2a R2b R3a R3b maxU Powe
61. ircuit emphasis it allows simulating an electronic system in the time domain pulse response as well as in the frequency domain noise behavior Our circuit is based on the Spice models of the BF862 March 2007 NXP Semiconductors and the model of the AD8011 Rev A 1997 Analog Devices The shaping filter is modeled noiseless by using the Laplace block from the analog behavioral modeling ABM library All simulations are made with PSpice version 16 0 from the company Orcad Cadence The good agreement between the simulations and the measurements can be noticed in the Figures 5 and 6 Awt hace Figure 5 The left part shows the result of a PSpice time domain simulation with an input charge of 1 pC In green the output signal from the LNP Preamp Vout peak 500 mV and in red the pulse after the shaping filter Vout shaped 390 mV is plotted the shaping filter has a peaking time of 650 ns Ihe right graph illustrates a noise simulation in the frequency domain with a detector capacitance of 270 pF With the curves in the lower part the impact of the different noise sources to the total output noise in red can be studied the y axis is a noise density with the unit V sqrt Hz It is obvious that the noise from the J FET is the dominating noise source The red curve in the upper part is the integrated output noise which results in 82 uVgys This value in respect to the 390 mV for an input charge of 1 pC corresponds to a simulated ENC of 1
62. iter Tran gt 8999 gt UM E HRB d DXX BIET Em e 5 cS Evaluate F V 1 A T are datla Al Reading and checking creut 2 Crouks d checked no Caiculating bias point for Eis d Ti y Transient Analysis finished Simulehon complete ed no emors Tiansiort Analysis Time step 2033 12 Time 1 600E 06 End 1 500E 06 la A pi For Help press Fl 9 oe osa Times 1 600 06 100 NENESSSERN Su stort 412 O Cerca 10 3 P3pice ics as SILNP_Preamp_T Filter AAA pr a 15 12 Low Noise 500 Coax Cable 1 8mm Huber Suhner K 01252HK 06 green colour Signal Connector IPX U FL Amphenol Typ A 1PA 113 200G1 Distrelec 13 82 60 with a tail of 1 15mm coax or Farnell 168 8075 cut the 300mm long 1 37mm coax cable in the mid then you get two cables with one U FL connector each Other side Lemo00 connector f e Typ 11 QLA 01 2 11 122 NE from Huber amp Suhner Shaper If it is not possible to use a fast flash ADC to capture the signal a shaper is needed for operation To achieve lowest noise the shaper must be optimized to the signal output of the preamplifier Specifications for Basel LNP preamplifiers SP883x Peaking time 650ns Ti 250ns Td 2us Input range 500 HiZ 0 2 5V 0 5V 0 5V 0 10V Gain ranges for example 0 5 1 2 and 4 8 16 adjustable to photodetector Output range depends on photodetector and ADC polarity single ended 500 differential
63. lems as long as the preamp doesn t run into saturation due to pile up The undershoot of the signal results from the AC coupling 22 uF at the output of the LNP Preamplifier Proper adjusting of the shaper eliminates this undershoot SP883d Manual Preamp page 35 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Event Rate Calculation amp Measurements M aximum Input Charge V5 LNP Preamplifier I 0 a Hi ae XL mer E us AN I I I I A Sepe 5 Br ex Ep E AM WE ME b Del i Tg M E Rr E Ll ji i i Ba I n 1r I I l I I l io 3 I LJ S IWE i j I I I I e I I l 4 A I I I I i I I I I I I I acaso la Seen nen pri F A dc ei I I I Ek L d I I I I ES RE m E UNE ECTS EIC DERE RP un A I i i is I Te Hy EYE ret hai RE la d E E 1 4 au I E I l pens Wii WE NE I I I I li m l u T E eee a ee be ee bp ee ee He fe ee Hl E i i i i 7 ul 7 f I I I I I I I I I I I O TELLER lt pUpU C A TUE ee Dina peas de E E zo doen pus AA LOLA i Mido aT YD E a I 2ALICEIL Eh ACTO gt gt A A J AO eee aes vaca li i XS n iT 1 M 3 i i ll l i DS i Wi e eel m A A6424 3d Reyog du LUNA DOE py es Basel T X Phy cher VETE
64. ne Isolation and protection VPTT RIE without silicone potting pa M Triode H2148 metal short DIANA er N RI MTT TNT yi m LIU 7m ANAT TTT e OA 3041 0 6 041 0 SHIT Pi IC Getter a9 97 95 MAR M MM mm BuU Getter EP IE wu Cw d A 1 2x d 0 8 j Betriebsparameter Photokathode Ov Dynode 500 V al Gitteranode 750 V 4 2 i xe P B C m S e TT Bialkalikathode 300 560 nm max 420 nm ii IC Getter Quanteneffizienz P 23 Gain G2 8 IC Internal Connection Dunkelstrom 0 1 nA Do not use PHOTOCATHODE Photo R2148MOD connected to LNP Version SP883c SP883d Manual Preamp page 8 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Short Data for type SP883d Max Bias Voltage 1500VDC 450V for APD Power Supply floating max 6V 6mA 1 5mA Power Supply for increased output voltage range limits rate 8V 2V max 10V 2V Quiescent power consumption 45mW Power consumption depending on rate and energy 90mW with 50 load Max single pulse input charge 4pC Max 500 kHz burst event rate ai sos E Output Signal Sensitivity ca 0 5V pC 50Q Output Signal Sensitivity ca 1V pC ohne Last Max output voltage with 6 6V power supply gt 2 5V0500 Max output voltage with 6 6V power supply gt 5V 1kQ Max output voltage with 8 2V power supply gt 3 5V
65. ompetition with fewer cables copper A good 6 side shielding around the preamp must be provided to insure low noise operation Connect the case shield to the preamp via mounting holes cable shields Supply GND To proceed low noise measurements all coaxial cables and connectors must be in perfect condition Prefere BNC before Lemo for low level analog signals Warm up the instruments The short rise time allows precise timing measurements timing resolution down to under 2ns possible depending on read out NPO Ceramic Capacitors are used in the critical signal path X5R X7R with appropriate temperature behaviour are used for decoupling and power supply filtering Test pulse coupling via a 1 pF Capacitor For use in high magnetic fields tested up to 1 2T but more expected The rectangular APD with smaller capacitance and higher bias voltage typ 630V is also possible but they are less radiation hard Radiation Hardness is not yet fully tested Implementation of suitable technology CMOS JFET The long tail of the LNP Preamp output results from the feedback network 1 pF 25Meg The resulting 25 us is a compromise between low noise performance and high rate capability pile up In principle this time constant can be reduced but you will get more noise The shaper after the preamplifier can reduce this fall time without any problems as long as the preamp doesn t go to saturation due to pile up The undershoot of the signal results from the AC c
66. or such a low noise design The proper frequency compensation is performed by the capacitor C13 47 pF in combination with R14 10 Ohm this leads to high frequency feedback to the inverting input of the operational amplifier Overshoot and ringing can be efficiently suppressed and this compensation also prevents from oscillations when no APD is connected or unshielded wires are used between the LNP Preamp and the APD The output of the operational amplifier is DC coupled via the feedback network 1 pF 25 Meg Ohm to gate of the J FET In parallel the output is AC coupled via a 1 uF capacitor and a 47 Ohm series resistor to the output of the LNP Preamp Therefore the output voltage is divided by a factor of two if it is terminated with 50 Ohm Note to the text 47pF is C15 not C13 as shown in diagram for tests use 1pF 1 Kapazis t 300pE fast gleich aber die Bias Spemmme liegt b ber typ 630V Deshalb wurden die HV Filter C s ge ndert Die 500V Widerstande sind f larzzeitiz hohere Spenmung speni ziert HV Biss Spammme smit mx h herer Fate k rzere Feedback nme constan z B IM we Filerwiderstand und ndert dams besser f r Burss den Nennverstidamestaleor gleich f r continous rate With a symmetrical supply voltage of 6 V the output voltage can swing symmetrically between the positive and negative supply when high continuous event rates at high energies occurs see Figure 4 The LNP Preamp draws a typical qui
67. oupling of the output Proper adopting of the signsal by the shaper can solve this Power up procedure Low Voltage power supply 6V should switched on first before the HV and therefore with signal Normal operation is given with a supply current of around 6mA on 6V and 1mA on 6V A higher supply current indicates ringing or defect Power up the HV via a ramp If not the ISEG HV supply will switch off because of relatively high current from loading the capacitors SP883d Manual Preamp page 10 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Application Hints for best operation To get lowest possible noise it is essential to take extremely care to the overall construction Example A real measured noise level is with good ground connection 2 9mV Ground via case and Power Supply with a poor GND only via coax shield 4 3mV That s a difference of roughly 50 So The best way of using the LNP charge preamp SP883x in an experimental setup is as following Connect the photodetector APD VPT T with a short Imax 100 mm coax cable to the LNP preamp or even better connect directly to the LNP preamp Leave the photodetector electrically floating this means that the APD ground comes from the LNP preamp via the outer shield of the short coax cable Place the photodetector coax cable LNP preamp in a electrically floating metallic e
68. p for pretests for VPTT RIE with 1 5kV VPTT LNP c d Preamp UNI BASEL E Prototype in Sandwich Technique for Hamamtsu VPT based on a modified VPT Preamp SP883c SP883 c d This solution provides Voltage Divider is now integrated on preamp Rtot 30 MegOhm 225 uA 750V 19mW instead of 3x220kOhm 21 14mA 850mW HV Caps are 1 5kV Total length without cables between ca 70 83 mm VPT 55mm Preamp 28mm This should be sufficient based on a total length with shortest mechanical Interface X5 and Y4 19mm of 88mm Contacting without space consuming tube socket or silicone potting The wires are soldered direct to the PCB to fit into the aluminum insert also at the corners Short lead connection lowest capacity from VPT to Preamp provides lowest noise and best immunity A plastic holder provides HV Isolation 40 1 5 28 310 AA VPT Body 40 1 5mm Exhaust cap lt 13mm eplO 2 PCB 28 mm vun Space for cable 10mm 7 Dimensions in mm not to scale 2010 11 pm TA CE TR r Le E A 5a ar sl Glossary Abbreviations LNP Low noise Low Power Preamplifier PCB Printed Circuit Board VPT Vacuum Photo Triode VPTT Vacuum Photo Tetrode LA APD Large Area Avalanche Photo Diode PMT Photomultiplier Tube RIE Research Institute Electron St Petersburg Ham H Hamamatsu Links Universit t Basel CH hitp azz physik unibas ch panda GSI Darmstadt D http www pand
69. r consumption VPTT Ham 10M O 10M 10M 10M 10M 750V15u h i2mW VPT Ham 10M o o o 10M 10M 750W25uUA_ 20mW APD Open Open Open Open Open Open Note all resistors 10M are 500V rated APD needs no divider only filter is implemented SP883d_Manual_Preamp page 15 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Round Divider PCB SP993d HV for Hamamatsu VPT T 1TaAmW S VPTT Ham 10M 10M 10M 10M 10M _ 750V 15uA_ 12mW VPT Ham 10M o O 10M 10M 750W25uA 20mwW Note all resistors 10M are 500V rated APD needs no divider only filter is implemented R12 R13 is each a single 22M 500V resistor instead of 2x10M in series to save space H1b is not implemented on the PCB to save space I m GIPELARDA 32 RE Lone Power HV Divider NES lent Ris TR Ts TES RR EX 4 VETT Fans 10M H10M 10M 10 10580 50M 150 9300 300V 1 JuA 12m V Fam toe U 70M TOM TOM TOW Unipolar Positive Pulse Output 0 5V pC 2 50O0hm ext VET Fam 10M 0M 0M 10M 10M5 S0ME 250V 500V 2 50A MW VPT am M 10 10 10 10M 10M P METERS 2 vi i Bia Voltage eol mem e A Dy kan i DVM mit 35 105 Monfahler 8052 8 TR des Ris im megattUe bai E l 5 icher Rate geringer Bawlins Shif VPTT Tewode VPTT cable ca 10 20pF max
70. reamplifier is a very sensitive instrument and therefore works similar to an antenna For low noise operation it is not recommended to operate the photodetectors and the preamp unshielded or in the same housing with motors i Better Left Distribution Board 6 Layer multilayer Board for LV amp HV distribution with signal shield and matched 50 Ohm impedance Right light tight shielded Alu Box with LED amp reference PMT Measurements taken December 17 2010 20 Preamp SP883d S N 3 with setup as shown above GND connection to Alubox Shaping with Ortec450 Gain ca x10 Ti 250ns Td 2us HV 1100V from Fluke 341A VPTT RIE no serial number Prototype received March 2010 from Mr louri Gousev RIE no silicon Photosensitive area partially covered Run 25 0M3 5 Ed e ae A 14 01kHz JA 70 03kHz E 13 74kHz 18 68 68kHz i i ne Hs StdDev Hs StdDev ua i 6Smy T 00mV M2 004s ch2 7 i3 0mV 17 Dec 2010 09 11 32 09 24 05 09 22 34 above VPTT RIE LED Puls from Left Noise sqrt 1 mV 0 5 mV ca 0 9mVrms 10 1 6E 19 562e SP771 optical coupling undefined Right Noise floor Ortec 450 with 50 ohms on input KO No light to VPTT RIE SP883d_Manual_Preamp page 46 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Beam Tests In August
71. rmal input of the shaping amplifier The 93 O resistor in the box is used to transmit the preamplifier ground signal to the differential reference input of the amplifier Both the normal and the differential reference cables are RG 62A U 93 Q coaxial cables Thus the 93 Q resistor in the box provides reverse termination of the differential reference cable This termination matches the 93 Q reverse termination included inside the preamplifier for the normal output signal To ensure that both cables are affected in the same way by electrical interference the two cables are twisted together in a spiral as they are routed to the amplifier When connected to the amplifier inputs the normal signal includes the desired preamplifier signal plus any interfering noise from ground loops or the environment The differential reference signal includes only the interfering noise Hence when the amplifier subtracts the differential reference from the normal signal the interfering noise is removed from the signal Amplifiers with differential inputs usually incorporate a differential gain balancing adjustment to allow matching of the gains on the two inputs for exact cancellation of the interfering noise Slow Control DCS http panda wiki gsi de cgi bin view EMC WebHome EPICS is used also for ISEG HV SP883d_Manual_Preamp page 42 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP88
72. s of initial versions are described in detail in the Panda TDR from June 2008 chapter 6 4 2 HV Divider Bleeder significantly lower current power 15 25uA than in standard applications around 0 5 1mA Example for commercial low current type Ortec 276L 200uA Disadvantage is a higher sensitivity to EMC MiniMelf resistor Inrush current limit tantal protection filter Zener Diodes Input protection device transient overvoltage polarity Low leakage diodes FET input protection Ceramic Caps X5R X7R COG NPO for low temperature operating range Tantal Caps Additional notes Gain lower gain higher feedback capacity change value of compensation capacitor Dynamic range higher positive power supply voltage while lowering the negative f e 8V 2V Compensation 100pF best for 0 100pF detector capacitance min 47pF for APD 270pF A higher cap value slows down the pulse rise time 100pF is also better when operated with 8V 2V A high Feedback resistor lowers the Johnson noise Circuit description for VPT preamp SP883a01 The AC coupled input stage consists of a low noise J FET of the NXP type BF862 It is specified with a typical input voltage noise density of 0 8 nV sqrt Hz at 100 kHz and at room temperature The J FET input capacitance is 10 pF and the forward transductance is typically 30 mS at a drain source current Ips of 5 mA Along with the 470 Ohm AC dominant drain resistor this transductance results in a typic
73. te input of the J FET is also decoupled by a 4 7 nF high HV capacitor A maximum APD bias voltage of 500 V can be applied and the total leakage current of the circuit under dry and clean conditions is below 2 nA As already discussed in the OVERVIEW APD BIAS AT HIGH EVENT RATES the voltage drop over the LP filter 1s critical at high event rates in combination with high energy a maximum current of 140 nA 1s then flowing trough the APD The actual series resistance of the LP filter is 32 Meg Ohm resulting in a maximum voltage drop of 4 5 V By applying the typical gain sensitivity of 3 per volt of the LAAPD this voltage drop corresponds to an energy error of 13 5 which is not acceptable see Figure 4 Reducing the series resistance of the LP filter to 1 Meg Ohm will diminish this energy rate error below 0 5 but the noise of the preamplifier will increase by 15 Using the same filter capacitor with 4 7 nF the cut off frequency will increase to 103 Hz which will also worsen the noise performance This cannot be exactly specified because it is depending on the noise characteristics of the bias voltage supply Larger HV filter capacitors would consume more space on the PCB The change of the values for the HV filter 3M instead of 32M and 15nF instead of 4n7 was made to decrease rate dependency of the bias voltage HV and therefore APD Gain Note this reduction in bias voltage gain dependency may result in a rate dependent temperature ris
74. the maximum possible burst rate reduce pile up the decay time can be reduced but then tradeoffs are e Higher noise and also e Higher power consumption e Higher voltage drop over HV filter e Other shaping time is needed 2 Higher rate 1 1 3MHz A shorter feedback time constant f e 2MOhm lt 4M4 ca 2 5us e Better for bursts e Same for continuous rate e Higher noise 3 Lower rate dependency lower bias resistance leads to more noise 4 Lower dynamic power consumption Change output impedance 750 930 or 110 O use other cables 5 Higher output amplitude no termination resistor doubles amplitude but maybe signal distortion 6 Higher output amplitude increase power supply voltage to maximum limit not specified SP883a03 Single APD High Rate 1 MHz Project R Novotny BESSIII SP883a0x Single APD 20mW Version Lower FET current Prototype Sample available SP883d_Manual_Preamp page 49 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T 8 APD readout model SP883d Preliminary Version Overview LNP Preamplifier ChAmp Charge Amplifier Familiy Evolution Chart Model Type Photo 2004 2005 12006 2007 12008 2009 12010 2011 Planned 2012 2013 Photodetector SP883 Ee A Prototypes Py AS 5x5 array 15 pcs c Giessen tests panda EMEN B Ol o 20xGiessen 60xBW Endc 51x Proto192 1x Beamtest BxZwieglinski 2x for KVI 2xlgorKonorov 1x A Wilms EMEN BEEN
75. umption of only 45 mW To set the 5 mA operating point of drain source current through the J FET a gate voltage in a range of 0 2 V to 0 6 V typically 0 3V depending on the DC characteristics of the individual J FET has to be applied This negative DC voltage is fed from the output of the operational amplifier via the 25 Meg Ohm resistor to the gate of the J FET The operating point Ibs 5 mA is fixed by the well filtered DC voltage applied to the inverting input of the operational amplifier This set point voltage is obtained by subtracting 2 5 V from the positive supply voltage 6 V by using a 2 5 V reference diode So the same voltage drop of 2 5V must also be present over the total drain resistor of 508 Ohm 470 Ohm 33 Ohm this results in a stabilized DC drain current of 5 mA The gate input of the J FET is decoupled by a 4 7 nF high voltage capacitor As the voltage drop over the LP filter for the VPT bias voltage has to be proven At high rates in combination with high energies a maximum current of 80 nA is flowing trough the VPT mainly drawn from the dynode bias voltage supply The planned series resistance of the LP filter is 40 Meg Ohm resulting in a maximum voltage drop of 3 2 V By using the typical gain sensitivity of 0 196 per volt of the VPT this voltage drop corresponds to a maximum energy rate error of 0 3296 which is acceptable By reducing the series resistance of the LP filter this energy rate error could be furth
76. uum photodetector with lower capacitance The realized mechanical shape was chosen to fit into the foreseen limited space for the Proto 192 crystals for the Panda FW endcap also with the longer glass tubes from Hamamatsu A round PCB shape was not possible for this space The Preamp is foreseen to work at 25 C but can al so be operated at higher temperatures but with more noise around 20 20 Vacuum Photo Tubes are not highly temperature sensitive in comparison to the APD s and isolate the Preamp termally from the crystal With APD s an additional temperature barrier or distance is necessary The originally concept was built for a range of around 10MeV to 10GeV but lower energies may be detected with a good measured setup A low power HV divider circuit for up to 1 5kV is also implemented This low power circuit is a new method because manufacturers of tubes recommends higher power consuming bleeder circuits Hence it was possible to implement the divider on the preamp itself in the cooled and therefore power loss critical sector of the detector This innovative concept reduces not only problematic temperature gradients to the photodetector and the crystals but also the amount of HV cables and therefore space and cooling losses To implement the additional HV circuit on the reduced area the preamp was split into two PCB s In addition it prevents from leakage currents to the input of the amplifier stage Each type of photodete
77. ved under the same conditions in the barrel with the LAAPD readout 2 MeVams At the same photon energy the signal from LNP Preamp connected to a VPT is a factor of nine smaller but also the noise is a factor of more than seven smaller compared with the LAAPD That s why the signal to noise is in the same order when using a VPT or an LAAPD for the readout of a PWO II crystal All these numbers above are related to the VPT type RIE FEU 190 used in the CMS ECAL By using new VPT the energy noise level will be reduced remarkable This may also be necessary because the noise level is increased as the shaping time is decreased Shorter shaping times are mandatory to cope with the expected high event rates in the endcap By decreasing the peaking time from 650 ns reference values to 200 ns the noise level is raised by around 25 So the noise floor with the more realistic shaping with a peaking time of 200 ns corresponds to 3 MeVaws SP883d Manual Preamp page 11 of 55 Physics Uni Basel CH 4056 Basel Basel LNP a discrete Preamplifier for VPT T amp APD readout model SP883d Preliminary Version Troubleshooting Guide Source Effect Typical source action Lk Noise pick up wires to detector Connect as close as possible to tube f e VPTT RIE with socket without silicone Switchmode Power Supply motors Low noise floating power supply well filtered vacuum pumps cooling etc shielded cables connect to GND on LNP side Switchmo

Manual Preamplifier SP883d - Nuclear and Particle Physics

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