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1. Figure 23 DSPEC jr 2 0 Presets Tab The values of all presets for the currently selected MCB are shown on the Status Sidebar These values do not change as new values are entered on the Presets tab the changes take place only when you start the next acqui sition or Close the Properties dialog When more than one preset is enabled set to a non zero value the first condition met during the acquisition causes the MCB to stop This can be useful when you are analyzing samples of widely varying activity and do not know the general activity before counting For example the Live Time preset can be set so that sufficient counts can be obtained for proper calculation of the activity in the sample with the least activity But if the sample contains a large amount of this or another nuclide the dead time could be high resulting in a long counting time for the sample If you set the ROI Peak preset in addition to the Live Time preset the low level samples will be counted to the desired fixed live time while the very active samples will be counted for the ROI peak count In this circumstance the ROI Peak preset can be viewed as a safety valve Enter the Real Time and Live Time presets in units of seconds and fractions of a second These values are stored internally with a resolution of 20 milliseconds ms since the MCB clock incre ments by 20 ms Real time means elapsed time or clock time Live time refers to the amount of time that t
2. Data Overflow Terminates acquisition when data in any channel exceeds 2 1 2x10 counts Digital Spectrum Stabilizer Stabilization Peak centroid zero and gain channel 2 to 16384 stabilization window width zero and gain 1 to 256 channels Zero Correction Resolution 64 channels with a minimum adjustment of 0 1 channel out of 16384 total channels Gain Correction Resolution 0 00025 from 99 5 to 100 5 in 4096 steps 3 1 1 Electrical and Mechanical Dimensions DSPEC jr 2 0 8 1 cmH x 20 3 cm W x 24 9 cm D 3 2 in x 8 in x 9 8 in DIM 11 2cmH x 3 13 cm W x 6 5 cm D 4 4 in x 1 25 in x 2 6 in Weight DSPEC jr 2 0 1 0kg 2 2 Ib DIM 240 gm 0 5 Ib Operating Temperature Range 0 to 50 C including LCD display 45 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 3 1 2 Connectors DETECTOR Multi pin connector 13W3 carries the following e Preamp Power 1 W only 12V 12V 24V 24V 2 GND Amp In Normal amplifier input Inhibit For TRP or gate Battery Power 5 12 V for DIM Control for HV SMART 1 HPGe detector control USB High speed USB communications 12 15V DC External power input from wall mounted de power supply 12 V dc lt 1 25 A center contact positive The connector is RAPC712 Switchcraft 5 5 mm x 2 5 mm 3 2 HPGe High Voltage Detector Interface Modules The DSPEC jr 2 0 offers high voltage supply flexibility in the form of modules t
3. Responses G0000000000075 lt CR gt Integral remaining reported as 0 G4294967295132 lt CR gt Integral reported as 4294967295 SHOW_LENGTH_SAMPLE Reports the number of points in the Insight mode waveform Response C01000088 1000 points in the waveform SHOW_LFR Tells whether LFR mode is enabled Responses IF LFR mode disabled SIT LFR mode enabled SHOW LIVE Reports the contents of the live time counter in units of 20 ms 50 ticks s See also CLEAR COUNTERS and SET LIVE Responses G0000000000075 lt CR gt Live time reported as O ticks G0000000001076 lt CR gt Live time reported as 1 tick 20 ms G4294967295132 lt CR gt Live time reported as 4294967295 ticks over 23000 days SHOW_LIVE_PRESET Reports the current live time preset in units of 20 ms 50 ticks s See also CLEAR_PRESETS and SET_LIVE_PRESET Responses G0000000000075 lt CR gt Live time preset reported as disabled G0000000001076 lt CR gt Live time preset reported as 1 tick G4294967295132 lt CR gt Live time preset reported as 4294967295 ticks SHOW_LIVE_REMAINING Reports the current live time remaining in units of 20 ms 50 ticks s See also SET_LIVE_REMAINING 76 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES Responses G0000000000075 lt CR gt Live time remaining reported as disabled G0000000001076 lt CR gt Live time remaining reported as 1 tick G4294967295132 lt CR gt Live time remaining reported as 4294967295 t
4. the number of low background points n 1 3 or 5 used n the number of high background points n 1 3 or 5 used The peak area uncertainty is calculated from SES G Bs where G is the sum of counts from the error spectrum from channels L to H ES from error spectrum 100 Area from ZDT spectrum Using our gamma ray spectrum analysis software such as GammaVision or ISOTOPIC 10 931010D 0914 1 INTRODUCTION e Inour WAN and ISOWAN analysis engines the peak fitting routine fits all the library peaks as singlets to calculate the peak centroid peak start and end channels and peak background A linear background under the peak is assumed during the peak fitting process e The error spectrum is always used to calculate the uncertainties of counts whenever needed For example if peak deconvolution is needed the error spectrum is used to find the best fit for the peak background 1 4 4 Choosing a ZDT Mode When the counting rate is essentially constant during the time required to acquire the spectrum the standard mode ZDT Off is the preferred mode only the uncorrected spectrum is col lected and stored in the spectrum file But if the counting rate varies significantly during the measurement time the standard mode will not yield the proper dead time corrected counting rate This can be most easily understood by noting that the uncorrected mode compensates for dead time losses by extending the
5. Programmable Vacuum HV interlock OASIS Programmable Current HV interlock OASIS 0 Explorable Stabilizer LIST_GAIN_ADJU LIST_ZERO_ADJU Has programmable input impedance MCS Advanced shaping time feature has no CUSP digiDART DSPEC jr 2 0 DSPEC Pro Selectable HV rise time SET SHOW LIST_HV_RISE SBS 60 Monitor command support SHOW MONI MAX LABEL V ALUE SMART 1 Detector support SHOW SMART DET SHOW SNUM DET SHOW HV RECO Nuclide report SET SHOW NUCL COEF SET SHOW ROI NUCL 3 SPECIFICATIONS 49 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Bit 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 50 Meaning Interactive Display Features Such as Nuclide Report Advanced Stored Spectra SH_SPEC_COUNT SET SHOW_SPEC_ID MOVE SET SHOW_VIEW in MCBs with Dual Port Memory or printer port interfaces LIST_VIEW in all MCBs Connected to MCB via RS 232 slow port No SET HV POSI SET_HV_NEGA ENA_NATand DIS NAI Low Frequency Rejector ENA DIS SHOW LFR Resolution Enhancer ENA DIS SH_RENHANCER SET SHOW RETABLE idx val SET MODE RELIST for Resolution Enhancer List Mode Readable Sample mode time per channel SH TIME SAMPLE Adjustable Sample mode time per channel SET LIST TIME SAMPLE List Mode data streamed and formatted as in digiBASE Supports ETP mode ENA DIS SHOW ETP List Mode data streamed and formatted as in DSPEC PRO SET SHOW LIST_PZ using floa
6. 12 volts since the last time the SOH was cleared DIM 24V State of Health This is OK if the 24 volt supply in the DIM has stayed within 200 mV of 24 volts since the last time the SOH was cleared Temperature State of Health This is OK if the detector temperature has stayed below the high temperature limit set in the detector since the last time the SOH was cleared This is available only for SMART 1 detectors High Voltage State of Health This is OK if the HV supply in the DIM has stayed within 200 V of specified bias voltage since the last time the SOH was cleared Shutdown State of Health This is OK if the detector shutdown has not activated since the last time the SOH was cleared Preamplifier overload State of Health This is OK if the preamplifier overload has not activated since the last time the SOH was cleared Security State of Health This is OK if the security test was passed at the end of the last spectrum acquisition This is available only for SMART 1 detectors 35 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Power State of Health This is OK if the power to the DIM was constant during the last spectrum acquisition 24 volts This is the current value of the 24 volt supply in the DIM as delivered to the detector 12 volts This is the current value of the 12 volt supply in the DIM as delivered to the detector 12 volts This is the current value of the 12 volt supply in th
7. are stored for a device when an acquisition is started See also SHOW TIME SET DATE SHOW DATE SET TIME START and SHOW TIME START SET TIME START hour min sec Sets the start time to the specified values Normally the start date and time are set automati cally whenever a device is started with the START command See also SHOW TIME START SET DATE START SHOW DATE START SET DATE and SET TIME 67 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SET TRIGGER POLARITY polarity This sets the polarity of the input trigger for the sample changer which occurs on the SAMPLERDYIN BNC to zero or 1 Zero means it is negative edge triggered and triggers on a high to low transition 1 means the trigger is positive edged and triggers on a low to high transition See also TRIGGER ENABLE TRIGGER DISABLE TRIGGER SHOW TRIGGER and SHOW TRIGGER POLARITY SET TRUE ticks Sets the true time counter to the specified number of ticks The number represents true time in units of 20 ms 50 ticks sec Normally this value is set by the DSPEC jr 2 0 during data acquisition See also CLEAR COUNTERS and SHOW TRUE SET TRUE PRESET ticks Sets the true time preset to the specified number of ticks 20 ms tick During data acquisi tion when the true time counter reaches the preset number of ticks the preset is complete and the acquisition is stopped Setting a true time preset to O ticks disables the preset See also CLEAR PRESETS an
8. on a reference graticule The Properties dialog remains active and can be used to change settings while viewing the pulses As none of the traditional analog signals are available in the DSPEC jr 2 0 this mode is the only way to display the equivalent amplifier output pulse Note that at the bottom of the window the marker channel is displayed in units of time To exit the InSight mode and return to the PHA display press Esc or go to the Insight section on the Amplifier 2 tab and click Stop The PHA mode is set to STOP when you enter the InSight mode The Status Sidebar changes from the PHA mode controls to the InSight controls for adjusting the peak display On the left is a vertical scrollbar for adjusting the vertical offset of the wave form The value of the offset is shown on the display Double clicking the mouse in the scrollbar will set the vertical offset to the vertical value of the channel at the marker position This lets you conveniently zoom in on a particular part of the waveform such as the tail for pole zero ing In the Auto trigger mode the display is updated every time a new pulse exceeds the trigger level To keep a single pulse displayed select Single Click Reset to refresh the display to see the next pulse There will usually be one or two pulses in the pipeline that will be displayed before any change entered will be seen If the trigger is turned off the display will be redrawn periodically even if no pu
9. value This sends the value to the port This command can be issued without entries for port and value because the DSPEC jr 2 0 has only one port If you wish to specify a port number it must be zero for this unit See also SHOW OUTPUT See also STEP OUTPUT SET OUTPUT HIGH output num Sets the Change Sample output to the high level The DSPEC jr 2 0 has only one sample changer BNC therefore if you include a value for output num it must be zero output num is provided for compatibility with other ORTEC instruments See also STEP OUTPUT SET OUTPUT LOW output num Sets the Change Sample output to the low level The DSPEC jr 2 0 has only one sample changer BNC therefore if you include a value for output num it must be zero output num is provided for compatibility with other ORTEC instruments See also STEP OUTPUT SET PEAK PRESET count Sets the ROI peak preset to the specified count During data acquisition when the contents of any channel of a device that has the ROI flag set reaches the peak preset count the preset is complete and the acquisition is stopped The actual number of counts in the ROI peak may exceed the preset value by a small number of counts due to the pipelined architecture of the DSPEC jr 2 0 Setting a peak preset to O counts disables the preset The peak preset may be set to from O disabled to 2147483647 counts See also CLEAR PRESETS and SHOW _ PEAK PRESET SET PZ num This sets the pole zero to num which
10. will provide a quotation Damage in Transit Shipments should be examined immediately upon receipt for evidence of external or concealed damage The carrier making delivery should be notified immediately of any such damage since the carrier is normally liable for damage in shipment Packing materials waybills and other such documentation should be preserved in order to establish claims After such notification to the carrier please notify AMT of the circumstances so that assistance can be provided in making damage claims and in providing replacement equipment if necessary Copyright 2014 Advanced Measurement Technology Inc All rights reserved ORTEC is a registered trademark of Advanced Measurement Technology Inc All other trademarks used herein are the property of their respective owners NOTICE OF PROPRIETARY PROPERTY This document and the information contained in it are the proprietary property of AMETEK Inc It may not be copied or used in any manner nor may any of the information in or upon it be used for any purpose without the express written consent of an authorized agent of AMETEK Inc ADDITIONAL WARRANTY STATEMENT Please note that the DSPEC jr 2 0 contains no user serviceable parts Breaking the seal on the case voids your warranty The DSPEC jr 2 0 should be opened only by ORTEC authorized service personnel iii iv Intentionally blank TABLE OF CONTENTS Installation page 19 IS age cg O dte oe A e
11. 0 is plug and play so installation is simple and is fully backward compatible with lower speed USB connections A nearly unlimited number of DSPEC jr 2 0s as well as any combination of other ORTEC USB instruments can be connected to the same computer using USB hubs As an ORTEC CONNECTIONS instrument DSPEC jr 2 0 works in both standalone and networked configurations Sample Changer Connections and Controls Improve your laboratory s productivity with the integrated sample changer connections and controls Dynamic Display DSPEC jr 2 0 displays the instrument ID name preset count conditions cur rent live and real time dead time percentage if active input count rate HV status and value and the serial number for SMART 1 detectors The display is an easy to read backlit LCD Desktop Housing The DSPEC jr 2 0 with the same small footprint as its predecessor the DSPEC jr sits right on the desktop Lightweight but rugged multiple DSPEC jr 2 0s can be stacked on top of one another via their interlocking cases without fear of sliding or tipping Use a USB hub to quickly connect multiple instruments to the computer The DSPEC jr 2 0 also offers these features e Highly stable peak shape and peak position with temperature and count rate a hallmark of our DSPEC family of MCBs Optimize detector performance for a given application from the computer using the InSight Virtual Oscilloscope e ORTEC s easy automatic pole zero adjustme
12. Detector Inter face Module DIM for single cable connection between the DSPEC jr 2 0 and the detector The DIM is designed to supply bias close to the detector so the cable carries only signal and low voltage power no longer is high voltage bias and its associated dangers carried over long distances SMART 1 Support Detectors equipped with the SMART 1 technology have their recom mended bias values preset at the factory No more shuffling through paperwork or looking for tags on the detector to find the right bias setting Simply turn on the electronics and the SMART 1 detector senses the detector temperature and applies the right high voltage bias Patent pending Patent number 6 327 549 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Our SMART 1 detectors also allow modern instruments like the digiDART and DSPEC jr 2 0 to monitor and display detector state of health SOH during acquisition including detector tem perature preamplifier power bias overrange and bias on off state This continuous SOH moni toring ensures the integrity of the acquired data A quick check of the SOH flag in the SMART 1 detectors shows if any parameter deviated from specification during the measurement This is vitally important for environmental samples that must be counted for long periods of time and regulatory driven samples where chain of custody integrity means everything High Speed USB Interface The DSPEC jr 2
13. GT om 12 State Of Heath OK GT DIM 24 State Of Heat OK or Temperature State Of Health OK Description 24V 12V 12 V 24V Figure 26 The SOH Status Tab within MAESTRO Comment The first four bits monitor the voltages coming from the DSPEC jr 2 0 If one of these values varies by more than 2 V the corresponding bit is set Temperature Set if the detector temperature increases and shuts down the HV HV voltage Overload Shutdown therefore the SHUTDOWN bit will also be set Set if the high voltage deviates by more than 300 V from the value you entered in MAESTRO Set if the preamplifier overloads for more than about 4 0 seconds Set if the preamplifier shuts down for any reason 89 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Bit 8 90 Description Security Power Comment At the start of the acquisition the DSPEC jr 2 0 queries the SMART 1 detector for its serial number The DSPEC jr 2 0 then writes a random number to the detector At the end of the acquisit ion both numbers are read from the detector and compared to the original values If there is a mismatch the Security SOH bit is set Set if the power fails during an acquisition AIDE SUD aria oa 31 AMUCOIMCITENCE 40 dado wth ase ee ab yes 31 Ballistic deficit and flattop 6 Coincidence anar a da ld ad dos 31 DSPEC jr 2 0 ADE SAD a e cob 31 amplifier sett
14. OVLD overload and the shutdown mode TTL ORTEC or SMART 17 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 If a SMART 1 detector is attached the DSPEC jr RT 36 6 LT 36 6 D 2 0 displays a line immediately beneath the high RTP 200 0 LTP 210 0 voltage line this line is blank for other detector types compare Figs 6 and 7 On the left are the DT 0 1 ICR 41 word SMART and the first eight characters of the tasse HU dues Gu SMART 1 detector s serial number This is the HV OV OVLD TTL same value returned by the SHOW_DET_SNUM command On the right is the detector temperature MCB ID 1 in kelvins DSPEC JR 2 0 V 002 J Figure 7 The DSPEC jr 2 0 Display for a The next line shows the ID number for this Non SMART 1 Detector DSPEC jr 2 0 as set by the MCB Configuration program and displayed in the Master Instrument List see the ORTEC MCB Connections Hardware Property Dialogs Manual for more informa tion on the MCB Configuration program and the Master Instrument List The last line on the display gives the firmware version for this DSPEC jr 2 0 2 1 1 2 Controls ON OFF To power up the DSPEC jr 2 0 press ON OFF It takes approximately 3 seconds for the display to appear To turn off the instrument press ON OFF The DSPEC jr 2 0 is designed to avoid accidental power down so acquisition isn t interrupted The display will ask you to confirm shutdown Press the backlight butto
15. The Low Frequency Rejector technology sur passes all signal processing methods for reducing the effects of microphonics and other sources of periodic noise for HPGe and Nal Tl spectrometry This advance in engineering senses the presence of noise that degrades spectral resolution and minimizes the effect by digital filtering As the leader in the development of mechanically cooled HPGe systems ORTEC is at the fore front in developing optimized electronics for these applications The result of our research and development projects for applications using mechanically cooled HPGe systems is a digital filter that can reduce the effect of virtually any source of periodic noise whether from microphonics ground loops or other sources With the DSPEC jr 2 0 we bring this technology to your laboratory in an economical package Zero Dead Time Correction The DSPEC jr 2 0 features our innovative ZDT mode of oper ation an alternative to the classical extended live time clock The ZDT method produces accurate results in all situations and overcomes completely some of the shortcomings of extended live time methods Moreover the new ZDT method overcomes some limitations in previous loss free dead time correction methods Most notably the ZDT mode does not require any manual adjustments and is capable of computing the statistical uncertainty of the corrected spectrum Single Cable Connection to Detectors DSPEC jr 2 0 uses the unique ORTEC
16. The Start Auto optimization button will remain disabled gray until the count rate is suitable Click it to start A series of short beeps indicates optimization is in progress When optimizing is complete the beeping will stop The process can take from 1 to 10 minutes depending on count rate but typi cally takes 5 minutes NOTE As with any system the DSPEC jr 2 0 should be optimized any time the detector is replaced or the Flattop Width is changed The effect of optimization on the pulse can be seen in the InSight mode on the Amplifier 2 tab Note however that if the settings were close to proper adjustment before starting optimization the pulse shape may not change enough for you to see In this situation you also may not notice Patent number 5 821 533 25 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 a change in the shape of the spectrum peaks The most visible effect of incorrect settings is high or low side peak tailing or poor resolution 2 3 2 Amplifier 2 Figure 14 shows the Amplifier 2 E for DSJ2 908 tab which accesses the advanced ae e na E a A i oltage out atus resets reset DSPEC jr 2 0 shaping controls pier Ampifer2 Amplfier PRO ADC Stabiizer including the InSight Virtual Oscil loscope mode Rise Time Flattop P izoo 4 Width 0 80 a The many choices of Rise Time let Tit 0 00000 you precisely control the tradeoff Pole Zero between resolu
17. Width fields to enter the channel limits directly or click Suggest Region If the marker is positioned in an ROI around the peak of interest Suggest Region reads the limits of the ROI with the marker and display those limits in the Start Chan and Width fields The ROI can be cleared after the preset is entered without affecting the uncertainty calcu lation If the marker is not positioned in an ROI the start channel is 1 5 times the FWHM below the marker channel and the width is 3 times the FWHM The net peak area and statistical uncertainty are calculated in the same manner as for the MAESTRO Peak Info command Marking the Overflow checkbox terminates acquisition when data in any channel exceeds 2 1 22x10 counts 2 3 10 MDA Preset The MDA preset Fig 24 can monitor up to 20 nuclides at one time and stops data collection when the values of the minimum detectable activity MDA for all of the user specified MDA nuclides reach the needed value Presets are expressed in Bq and are evaluated every 40 seconds The detector must be calibrated for energy in all spectroscopy applications and for efficiency in all applications but MAESTRO The MDA presets are implemented in the MCB i e the entries you make on this screen are saved in the MCB memory and have no direct link to MDA methods selected in the analysis options for applications such as GammaVision ScintiVision ISOTOPIC etc The MDA preset calculation uses the following
18. about the window of interest Example Responses D0000016384094 lt CR gt Window of interest reported as starting at channel 0 and continuing for 16384 channels D0000008192092 lt CR gt Window of interest reported as starting at channel 0 and continuing for 8192 channels D0819208192112 lt CR gt Window of interest reported as starting at channel 8192 and continuing for 8192 channels SHOW_ZDT Reports if ZDT mode is enabled Responses IF ZDT mode disabled IT ZDT mode enabled SHOW ZERO ADJ Returns the value of the zero offset for the zero stabilizer SHOW ZERO CHANNEL Reports the center channel for the stabilizer zero peak See also SET ZERO CHANNEL SET ZERO WIDTH and SHOW ZERO WIDTH 85 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Responses C00000087 CR Zero channel has not been set C00002089 CR Zero channel is channel 2 lowest possible channel C16382107 CR Zero channel is channel 16382 highest possible channel SHOW ZERO STABILIZATION Reports the state of zero peak stabilization See also ENABLE ZERO STABILIZATION and DISABLE ZERO STABILIZATION Responses IT lt CR gt Zero stabilization is currently enabled IF lt CR gt Zero stabilization is currently disabled SHOW_ZERO_WIDTH Reports the current width for the stabilizer zero peak See also SET_ZERO_WIDTH SET_ZERO_CHANNEL and SHOW_ZERO_CHANNEL Responses C00001088 lt CR gt Zero width has
19. are discussed in detail in the MAESTRO user manual High Voltage About Status Presets MDAPreset Amplifier Amplifier 2 Amplifier PRO ADC Stabilizer The value in each Adjustment sec Gain Stabilization Enabled Zero Stabilization Enabled tion shows how much adjustment E O Center Chan 0 is currently applied The Initialize Width 1 Width 1 buttons set the adjustment to 0 If E uggest Region Suggest Region the value approaches 90 or above Austin eem the amplifier gain should be adjusted Initialize 0 Initialize 0 so the stabilizer can continue to func tion when the adjustment value reaches 100 the stabilizer cannot make further corrections in that direction The Center Channel and Width fields show the peak currently used for stabilization Figure 19 DSPEC jr 2 0 Stabilizer Tab To enable the stabilizer enter the Center Channel and Width values manually or click the Suggest Region button Suggest Region reads the position of the marker and inserts values into the fields If the marker is in an ROI the limits of the ROI are used If the marker is not in an ROI the center channel is the marker channel and the width is 3 times the FWHM at this energy Now click the appropriate Enabled checkbox to turn the stabilizer on Until changed in this dialog the stabilizer will stay enabled even if the power is turned off When the stabilizer is enabled the Center Channel and Width cannot be ch
20. as the manuals for GammavVision ISOTOPIC and our other spectroscopy software For the purposes of this manual when we refer to MAESTRO we mean the ORTEC MCA emulator analysis application you are using e g MAESTRO GammaVision ISOTOPIC 15 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Intentionally blank 16 2 GETTING STARTED 2 1 The DSPEC jr 2 0 2 1 1 Front Panel Figure 5 shows the DSPEC jr 2 0 front panel Figure 5 DSPEC jr 2 0 Front Panel 2 1 1 1 The Display The DSPEC jr 2 0 has a 240 x 160 pixel LCD display for viewing presets high voltage setting and status stabilizer settings SMART 1 detector status and shutdown mode Figure 6 shows the layout of display for a DSPEC jr 2 0 with a SMART 1 detector RT RTP LT and LTP are respectively the actual real time real time preset live time and live time preset DT and ICR are the dead time in percent and input count rate in counts per second CPS RT 36 6 LT 36 6 RTP 200 0 LTP 210 0 DT 0 1 ICR 41 GainStab OFF ZeroStab OFF HV 0 V SHDN SMART SMART 42 N21741A 92 K MCB ID 1 L DSPEC JR 2 0 V 002 Figure 6 The DSPEC jr 2 0 Display Showing Presence of a SMART 1 Detector GainStab and ZeroStab show the current setting for the gain and zero stabilizers respectively The next line shows the current high voltage setting HV the current high voltage status ON OFF SHDN shutdown or
21. buffer will always be shown in PHA mode The display will return to the InSight mode when you return to the first 28 931010D 0914 2 GETTING STARTED DSPEC jr 2 0 If you exit the program with the DSPEC jr 2 0 in InSight mode it will be in InSight mode on the next startup The display can include a Mark to indicate one of the other signals shown in Fig 16 The Mark is a solid color region displayed similarly to that of an ROI in the spectrum This Mark can be used to set the timing for the gate pulse It can also be used to set the shaping times and flattop parameters to get the best performance For example suppose you want to get the best Aan LDisc resolution at the highest throughput possible By viewing the pulses and the Gate pileup reject marker you can increase or decrease the rise time to obtain a Peak minimum of pileup reject pulses Mark Types El none PileU pReject NegBLDisc BaseLineR Figure 16 Mark Display Selection For the Mark choose either points or filled to the zero line display This is controlled by the selection in the Display Preferences menu item That choice does not affect the PHA mode choice The colors are the same as for the PHA mode None No channels are marked in the display PileUpReject The region marked indicates when the PUR circuit has detected pileup and is rejecting the marked pulses NegBLDisc This shows when the negative baseline discri
22. formula 38 931010D 0914 where 2 GETTING STARTED r Properties for DSJ2 908 Amplifier Amplifier2 AmpifierPRO ADC Stabilizer High Voltage About Status Presets MDA Preset MDA Preset Nuclide Energy i MDA Preset Coefficients Correction cA A 10 000000 Nuclide Pu 238 B 10 000000 Energy keV C 0 000000 Figure 24 DSPEC jr 2 0 MDA Preset Tab MDA a b c Counts Live time CorrectionFactor a b and c are determined by the MDA criteria you choose Counts is the gross counts in an ROI that is 2 5xFWHM around the target peak energy Live time is evaluated in 40 second intervals for the MDA presets CorrectionFactor is the product of the calibration efficiency at the specified peak energy and the peak s branching ratio yield as listed in the working active library NOTE MAESTRO does not support efficiency calibration The efficiency component in the CorrectionFactor 1s set to 1 0 the preset field is labeled Correction instead of MDA and the preset is based on counting activity cA instead of becquerels You can enter the MDA preset either in counts or corrected for factors such as sample volume attenuation or calculated efficiency For example if you manually calcu late the efficiency for a peak you can enter a corrected MDA target value by multi plying the desired MDA value times the calculated efficiency and entering the product as the Co
23. has the effect of altering the resolution of the ADC from 14 bits conversion gain 16384 to 9 bits conversion gain 512 for the device See also SHOW GAIN CONVERSION Legal Commands SET GAIN CONVERSION 0 lt CR gt Conversion gain set to default 16384 SET GAIN CONVERSION 512 CR Conversion gain set to 512 channels SET GAIN CONVERSION 1024 CR Conversion gain set to 1024 channels SET GAIN CONVERSION 2048 CR Conversion gain set to 2048 channels SET GAIN CONVERSION 4096 lt CR gt Conversion gain set to 4096 channels SET GAIN CONVERSION 8192 lt CR gt Conversion gain set to 8192 channels SET GAIN CONVERSION 16384 lt CR gt Conversion gain set to 16384 channels SET GAIN FINE value Sets the fine gain to value Value is a floating point value from 0 333 to 1 0 See also SHOW GAIN FINE SET GAIN NEGATIVE Sets the amplifier input polarity to negative SET GAIN POSITIVE Sets the amplifier input polarity to positive SET GAIN PRESET count No function in the DSPEC jr 2 0 included for backward compatibility SET GAIN WIDTH chans Sets the width in channels for the stabilizer gain peak The gain width must be chosen such that the beginning channel is no lower than channel 0 and the ending channel is no higher than the maximum channel as determined by the conversion gain The gain channel and width must be set before gain stabilization can be enabled The absolute minimum width for the gain peak is 3 channels and the a
24. must be between 0 and 4095 See also ENABLE PZ AUTO SHOW PZ and DISABLE PZ AUTO SET RADIX BINARY Not used in the DSPEC jr 2 0 included for backward compatibility 65 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SET ROI start chan number of chans Sets the ROI flags for the specified channels This command can be used multiple times to set ROI flags without affecting previously set flags ROI flags specify channels within a device that are considered for ROI integral and ROI peak presets SET ROI MDA start numchans PeakNumber Sets the region to use to compute the gross counts in the MDA calculation PeakNumber is an optional parameter assumed 0 if not present that specifies which of up to 20 0 19 MDA Presets to change SET ROI SAMPLE num Selects which control signals are displayed as an ROI on the captured waveform Only a single bit can be turned on at a time The following signals can be selected with the associated bit Bit 0 Pileup reject Bit 1 Negative baseline threshold Bit 2 Baseline restorer gate Bit 3 Positive baseline threshold Bit 4 Busy Bit 5 Gate Bit 6 Reserved Bit 7 Peak detect Bit 8 Reserved SET ROI UNCERTAINTY start chans Sets the region to be used for the uncertainty preset calculation See also SHOW ROI UNCERTAINTY SET SEGMENT Not used included for backward compatibility SET SHAP FLAT value Sets the width of the flattop to value Valu
25. not been set C00003089 lt CR gt Zero width is 3 channels lowest possible width C00256100 lt CR gt Zero width is 256 channels highest possible width in Gauss mode C16383108 lt CR gt Zero width is 16383 channels highest possible width in point mode with zero channel set to 8192 START seg mask Starts the acquisition of spectral data The optional segment mask is provided for compati bility with other MCBs and may be any value from 0 to 65535 but is ignored by the DSPEC jr 2 0 START_FLAT_AUTO Performs optimization of PZ and flattop correction for a single rise time instead of all rise times START_OPTIMIZE Starts optimization of PZ and flattop correction for all rise times 86 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES START_PZADJUST_AUTO Starts the automatic PZ process The automatic PZ is not complete until indicated by the auto PZ status bit This bit is returned by the SHOW_STATUS command Spectral data can be corrupted if automatic PZ is initiated while a device is collecting data Execution Errors 131136084 lt CR gt The command was attempted while the amplifier was set for a transistor reset preamplifier No action was taken STEP_OUTPUT Causes a pulse to be output on the Change Sample output port The level of the Change Sample output is changed then returned to the level present when the STEP_OUTPUT com mand was received The duration of the intermediate level varies but is never less than 2
26. real counting time Hence a sample containing both a short lived high activity isotope and a long lifetime lower activity isotope will experience very high dead time losses during the first few seconds of the measurement as the short lifetime isotope decays rapidly This high dead time will cause the counting time to be extended after the short lived isotope has decayed to zero activity and the system will count the low activity isotope for the extra time Consequently the average activity of the short lived isotope will be under estimated If you anticipate significantly varying counting rates during the time taken to acquire the spec trum the CORR ERR ZDT mode should be used The CORR ERR mode corrects for dead time losses over minuscule time intervals by adding counts to the ZDT spectrum in proportion to the instantaneous ratio of real time to live time Thus the dead time correction can correctly track rapidly changing counting rates The CORR ERR mode should be used whenever the counting rate might change significantly during the measurement time In addition to the rapidly decaying isotope example above the CORR ERR mode should be used when monitoring cool ing water flow from a nuclear reactor The CORR ERR mode accommodates brief bursts of high activity in the water flowing past the gamma ray detector Both the corrected and error spectra are stored in the resulting spectrum file Note that the counts in the ZDT spectrum must be div
27. the DIM s Inhibit BNC Signal must occur prior to and extend 0 5 us beyond peak detect Software selectable as off coincidence or anticoincidence Digital Filter Shaping Time Constants e Rise time 0 8 us to 23 us in steps of 0 2 us e Flattop 0 3 to 2 4 in steps of 0 1 ps PFor the legacy LO AX and IGLET X detector types the respective energy ranges are 94 keV 6 MeV and 8 keV 500 keV 43 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 Dead Time Correction Extended live time correction according to Gedcke Hale method Accuracy area of reference peak changes lt 3 from 0 to 50 000 cps Low Frequency Rejector LFR When ON removes low frequency lt 3 kHz input noise from spectrum Linearity e Integral Nonlinearity lt 0 025 over top 99 5 of spectrum measured with a mixed source Fe at 5 9 keV to Y at 1836 keV e Differential Nonlinearity lt 1 measured with a BNC pulser and ramp generator System Temperature Coefficient e Gain lt 50 ppm C typically 30 ppm C e Offset lt 3 ppm C with rise and fall times of 12 us and flattop of 1 us similar to analog 6 us shaping Pulse Pileup Rejector Automatically set threshold Pulse pair resolution typically 500 ns Automatic Digital Pole Zero Adjustment Can be set automatically or manually Remote diagnostics via Insight Virtual Oscilloscope mode in MAESTRO Digital Gated Baseline Restorer Software controlled adjustment of th
28. the InSight sidebar Fig 15 For a low count rate system the value will remain at about 90 Preamplifier Type Choose Transistor Reset or Resistive Feedback Your choice will depend on the preamplifier supplied with the germanium detector being used Optimize The DSPEC jr 2 0 is equipped with both automatic pole zero logic and automatic flattop logic The Start Auto optimize button uses these features to automatically choose the best pole zero and flattop tilt settings Note that if you select Transistor Reset as the preampli fier type the optimization routine does not perform pole zeroes During optimization pole zeroes are performed for several rise time values and the DSPEC jr 2 0 cycles through all the rise time values for the determination of the optimum tilt values As all of the values for all the combinations are maintained in the DSPEC jr 2 0 you do not have to repeat optimization for each possible rise time Optimization requires a source with sufficient activity to register between 800 cps and 5000 cps Arrange the detector in its final configuration Unmark the LFR checkbox on the Amplifier PRO tab you cannot optimize with LFR mode enabled see Section 2 3 3 turn on the HV so the instrument is processing pulses then place the source on or near the detector endcap A count rate guidance message on the lower left of the Amplifier page will help you position the source to deliver the correct count rate for optimization
29. the USB port on the computer 4 Runthe MCB Configuration program to build a list of available ORTEC MCBs 2 2 1 Step 1 Install the CoNNECTIONS Driver Update The first step is to install the CONNECTIONS Driver Update Kit P N 797230 according to its instruction sheet This software must be installed before MAESTRO can be installed The update kit s instructions tell how to install CONNECTIONS enable disable the drivers for your ORTEC MCB s and share ORTEC instruments across a network On the Instrument Families page be sure to mark the USB based instruments checkbox as shown in Fig 9 Otherwise the DSPEC jr 2 0 will not be able to communicate with the computer and MAESTRO software At the end of installation you will be directed to restart the computer 19 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Instrument Setup E 4 Instrument Families Please check all items in this USB based instruments list that are connected to or O DPM USB installed in this computer O Dual Port Memory plug in cards ISA slot Click Done when you are O TRUMP PCI cards finished O DART or any other printer port based device O microBASE Item Description amp O Miniature MCA miniMCA 155 Check this entry if you a O maca have any ORTEC USB amp L digiDART RS232 based instrument except amp L DSPEC jr R5232 ES Ol mcs Pci O DigiBASE E Local Instrument list lt No instruments found gt Allow other co
30. until it reaches a peak amplitude at a time specified by the currently selected rise fall time this is the Rise Time parameter entered on the Amplifier 2 tab under Acquire MCB Properties see Section 2 3 2 Beyond this peak amplitude time the pulse falls back to the baseline to allow a subsequent gamma ray to be processed If all the charge has not been collected by the detector by the desig 6 931010D 0914 1 INTRODUCTION nated time for peak amplitude there will be a deficit in the measured peak amplitude and a broadening of the pulse width all caused by the slow charge collection The deficit in amplitude is called the ballistic deficit Obviously events that result in a faster charge collection time will suffer less deficit and less increase in pulse width than those yielding a slower charge collection time even though the deposited energy was identical Thus the ballistic deficit resulting from variable charge collection times broadens the energy resolution for that gamma ray If the longest charge collection time is negligible compared to the rise time of the filter pulse the ballistic deficit will be imperceptible and the energy resolution will not be degraded Thus at the 10 to 20 us rise times typically selected for optimum signal to noise ratio 1 e minimum peak FWHM at low energies the ballistic deficit problem can be ignored Long rise times create higher dead times and depress the maximum counting rate limit If it i
31. used to determine exactly how many pulses at any energy were pro cessed by the spectrometer The corrected spectrum gives the best estimate of the total counts that would have been in the peak if the system were free of dead time effects The uncertainty spectrum can be used to calculate the counting uncertainty channel by channel in the corrected spectrum NOTE When the spectrometer is placed in ZDT mode the throughput of the instrument is reduced somewhat as extra processing must be done on the spectrum therefore if the gamma ray flux is not changing as a function of time but absolute highest throughput is desirable you might wish to store only the LTC spectrum in the MCB memory 1 4 2 NORM_CORR ZDT and Uncorrected Spectra Stored When the ZDT mode is set to NORM_CORR the two spectra stored are the LTC spectrum and the ZDT spectrum corrected for the dead time losses real time only Unfortunately in the analysis of the ZDT spectrum the uncertainty of the measurement cannot be determined using either spectrum NOTE This mode is not useful for quantitative analysis if the counting rate varies significantly during the measurement time particularly if the user desires an accurate counting rate and standard deviation calculation When you select the NORM CORR mode the spec troscopy software ignores the ZDT spectrum and analyzes the LTC spectrum as it would for the Off ZDT mode 1 4 3 CORR ERR ZDT and Error Spectra Stored
32. 0 channels long D0215000150086 lt CR gt First ROI group starts at channel 2150 and is 150 channels long D0000000000072 lt CR gt No ROI groups to report SHOW_ROI MDA Reports the start channel and number of channels used in the MDA preset calculation Example Response D0700000050ccc Calculation is performed on channels 7000 7049 SHOW ROI SAMPLE Displays the ROI Sample setting See also SET ROI SAMPLE Responses C00001088 80 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SHOW ROI UNCERTAINTY Reports the start channel and number of channels used in the uncertainty preset calculation See also SET ROI UNCERTAINTY Response D0700000050ccc Calculation is performed on channels 7000 7049 SHOW SEGMENT Returns the current segment number Always 1 for the DSPEC jr 2 0 SHOW SHAPE CUSP Not used by the DSPEC jr 2 0 included for backward compatibility SHOW SHAP FLAT Reports the width of the flattop in us See also SET SHAP FLAT Responses SHAP FLAT 0000000000001 2 SHOW SHAP RISE Displays the rise time setting in us See also SET SHAP RISE Responses SHAP RISE 0000000000003 2 SHOW SHUTDOWN Shows the type of HV shutdown selected Responses FORT ORTEC mode selected FTTL TTL mode selected FSM1 SMART 1 mode selected SHOW_SHUT_ACTUAL Returns the current status of the bias remote shutdown input signal This command is valid whether the bias supply is turned on or off Responses IT Shutdo
33. 2 Help 7 Station 6 Right 8 Station 5 Left 11 Station 3 Renumber Al 13 Station 4 Renumber All 14 DSPEC PRO MCB 129 Renumber New Instr Input System Figure 10 MCB Numbering and Descriptions 21 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 2 2 4 1 Configuring a New Instrument The first time a new instrument is detected the This is the first time you have configured these detectors dialog shown in Fig 11 will remind you that E gea i all new instruments must be assigned a unique numbers for your detectors non zero ID number Click OK You can either manually change the ID Number and Description as described in the next subsection or you can click the Renumber New button Figure 11 New Instruments Must Have a Non to renumber only the new instruments Zero ID Number NOTE We strongly recommend not using the Renumber All button In addition we strongly recommend not renumbering MCBs that belong to other users as this could affect the interaction between their MCBs and their ORTEC software for instance if they control their MCBs with JOB files e g the JOB file command SET DETECTOR 5 or use the GammaVision or ISOTOPIC spectroscopy applications See also the NOTE FOR MULTIPLE USERS ON A NETWORK in the next section 2 2 4 2 Customizing ID Numbers and Descriptions If you wish you can change the instrument ID Numbers and Descriptions by double clicking an instr
34. AR ALL or CLEAR HV HEALTH At the end of the acquisition the DSPEC Pro reads the SOH and if any bit is set displays a warning message If no bits are set no message is displayed this means there was no problem during the acquisition The SOH status is saved with the spectral data in the SPC file as part of the QA data MAESTRO GammaVision and other ORTEC programs can monitor the status of the SOH bit for the current spectrum on the Status tab under Acquire MCB Properties In addition user developed programs may read and write the SOH register Chapter 4 provides the commands for reading and interpreting the SOH settings see Appendix A for a table of SOH bit definitions 1 6 Host Computer and Software Requirements The DSPEC jr 2 0 is completely computer controlled and can be operated with any suitable ORTEC CONNECTIONS software including the supplied MAESTRO MCA Emulation Software A65 BW communicating via the supplied version of CONNECTIONS The current version of MAESTRO runs under Microsoft Windows 8 7 XP Professional SP3 1 7 About this Manual This manual describes the DSPEC jr 2 0 tells how to connect it in a complete spectroscopy system gives instructions on configuring the hardware settings such as high voltage presets 14 931010D 0914 1 INTRODUCTION and gain and supplies the hardware commands and responses Complete details on using the control software are in the MAESTRO Software User s Manual as well
35. C jr 2 0 and the current conversion gain for each segment The record is organized as follows J1638400001aaaaa00000 65 zeros here for total of 75 zeros 00000ccc where aaaaa represents the conversion gain for the one and only segment in the currently selected device and ccc represents the record checksum See the section on response records in this chapter for more information about response records and checksums 69 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SHOW CONFIGURATION MASK Returns two masks the first of which can be anded with data from the MCB to clear the ROI bit from the data When the second mask value is anded with data from the MCB the data bits are removed and only the ROI bit remains Response CONF MASK 02147483647 02147483648 SHOW CONFIGURATION UART Reports the baud rate parity option number of data bits and number of stop bits for the serial interface Responses F09600N81 9600 baud no parity 8 data bits 1 stop bit F19200E82 19200 baud even parity 8 data bits 2 stop bits F02400071 2400 baud odd parity 7 data bits 1 stop bits SHOW_CORRECTION_FLAT Shows the flattop correction value See also SET_CORR_FLAT Responses CORR_FLAT 000000000000000 SHOW_CRM Returns the current reading of the count rate meter Response G0000050781096 Current input count rate is 50781 counts s SHOW_DATA_APPLICATION string If string matches stringl in a
36. D5J2 908 Sample Acquisition Start Time Access 20 13 00 Friday November 08 2019 Read Write Acquisition Mode PHA Serial Number 00908 Firmware Revision D5J2 001 Figure 21 DSPEC jr 2 0 About Tab r Properties for DSJ2 908 Amplifier Amplifier2 AmpifierPRO ADC Stabilizer High Voltage About Status Presets MDAPreset Ok y DIM 24V State Of Health OK y DIM 12V State Of Health OK DIM AZ State OfHealth OK y DIM 24V State Of Health OK Jor Temperature State Of Health OK Figure 22 DSPEC jr 2 0 Status Tab by more than the allowed limit the ERR is set until cleared by the program The numeric values are displayed in the units reported by the DSPEC jr 2 0 Security Detector temperature and Live detector temperature are available only for SMART 1 detectors For non SMART 1 detectors they show N A 34 931010D 0914 2 GETTING STARTED The parameters displayed are Detector State of Health This is OK if all the SOH are OK and ERR if any one is ERR DIM 24V State of Health This is OK if the 24 volt supply in the DIM has stayed within 200 mV of 24 volts since the last time the SOH was cleared DIM 12V State of Health This is OK if the 12 volt supply in the DIM has stayed within 200 mV of 12 volts since the last time the SOH was cleared DIM 12V State of Health This is OK if the 12 volt supply in the DIM has stayed within 200 mV of
37. EC jr 2 0 is on the list If it is not listed shutdown and restart the computer then re run the MCB Con figuration program according to Section 2 2 4 41 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 e Seethe CONNECTIONS Driver Update Kit instructions for more detailed information on using MCB Configuration 42 3 SPECIFICATIONS 3 1 DSPEC jr 2 0 Display 240 x 160 pixel backlit LCD provides status information instrument ID bias infor mation live and real time Concurrent Connections Limited by the computer and supporting USB hubs ORTEC CON NECTIONS software supports up to 127 USB connected devices per computer Maximum System Throughput gt 100 000 cps depends on shaping parameters System Gain Settings e Coarse Gain Settings 1 to 32 in binary steps 1 2 4 8 16 32 e Fine Gain 0 45 to 1 The available range of gain settings supports all types of HPGe detectors Specifically the fol lowing maximum energy values are achievable using the standard ORTEC preamplifier maxi mum to minimum gain e COAX 187 keV 12 MeV e GLP SLP 16 5 keV 1 MeV Amplifier Input Polarity Selectable via software System Conversion Gain Computer selectable as 16384 8192 4096 2048 1024 or 512 channels Preamplifier Computer selectable as either resistive or TRP preamplifier ADC Gate Not available for PLUS transistor reset preamplifier or SMART 1 detectors Accepts a positive TTL input via
38. ENA DIS_CLICK Software readable thermistor SHOW_THERM 931010D 0914 Bit 55 56 57 58 39 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 17 78 79 80 81 82 83 84 85 86 87 88 89 90 Meaning Floating point fine gain SET SHO VERI LIST_GAIN_FINE Software enabled pileup rejector ENA DIS SHO_PUR SET VERI_WIDT_REJ Alpha style HV power SHOW_HV_CURRENT Software readable vacuum SHOW_VACUUM Acquisition alarms ENA DIS SHO_ALARM Hardware acquisition trigger ENA DIS SHO_TRIG Ordinal numbers for shaping times SET_SHAP 0 SET_SHAP 1 Query gain ranges LIST VERI_GAIN_FINE _COAR _CONV Routable inputs SET SHOW INPUT ROUTE External dwell support ENA DIS DWELL EXT Selectable SUM or REPLACE MCS modes ENA DIS SUM External start of pass support ENA DIS SHO START EXT Explorable with MCS list commands LIST SOURCE LIST LLSCA LIST ULSCA Device supports the MDA preset Software selectable ADC type MatchmakerTM Has ability to daisy chain MCBs DART ZDT functions available DSPEC Plus DSPEC Plus style Insight triggering LIST SET TRIG SAMP Multiple inputs per connection for example OCT TE Plus Hardware count rate meter SH CRM Has multiple ZDT modes SET SHOW LIST MODE ZDT Has multi nuclide MDA preset Has MCS Replace then Sum Mode SET RPLSUM Has programmable external dwell voltage capability No Peak Preset feature M CA and OASIS Programmable pulser OASIS
39. In the CORR ERR mode the estimation of the statistical uncertainty is stored in place of the LTC spectrum and is referred to as the error spectrum ERR In this mode the ZDT spectrum DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 is used to measure the counts in a peak and the error spectrum is used to determine the uncer tainty of the measurement made in the corrected spectrum For example if the area of a peak is measured in the corrected spectrum by summing channels 1000 to 1100 the variance of the measurement can be determined by summing the counts in channels 1000 to 1100 in the error spectrum Or shown another way the counts in channel 7 can be expressed as N 7 y V i with a 1 sigma confidence limit where N is the corrected spectral data and V is the variance error spectral data The live time is set to the real time within the analysis engine during the analysis of ZDT spectra A CORR ERR spectrum is analyzed as a regular spectrum most of the time with a few exceptions as listed below e To calculate the peak area uncertainty the error spectrum is used If the peak limits are from L and H channels then the background variance is calculated as B n n B n n x H L 1Y var 4 B sum of background counts for the channels adjacent to the peak start low energy channel L B sum of background counts for the channels adjacent to the peak end high energy channel H n
40. MC VUA bu de UN Bele a eMe 14 2 GETTING STARTED 502 eE RA adv dt bes 17 Pie The DSPEC Jr IA A O OS 17 2 bI A it tna v ROI bes gita hk apod Girne uoc ene podes 17 2311 The Display 9 Powe Rr ERA Rt I ERE LANGUE PEE ASA 17 21 122 Controls rs does Sende o aee tS esr pes gd Lb be RN S kde 18 2 12 eal Paneles vs o A EI E E DM BEAD bese 18 2 2 Software and Hardware Installation 22 Ear PR S ote eee es 19 2 2 1 Step 1 Install the CONNECTIONS Driver Update o oo oomooooo 19 2 2 2 Step 2 Install MAES TRO nce oia keit cmo oet n eem ks eae 20 2 2 3 Step 3 Connect the DSPEC jr 2 0 to the Computer 20 2 2 4 Step 4 Run MCB Configuration to Communicate With Your MCBs 21 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 2 2 4 1 Configuring a New Instrument 0 0 2 e cee eee eee 22 2 2 4 2 Customizing ID Numbers and Descriptions 22 2 2 5 Attaching More Than One DSPEC jr 2 0 to the Computer 23 2 2 6 Connecting to and Disconnecting from the Computer 23 2 3 DSPEC jr 2 0 MCB Properties in MAESTRO eese 23 2 9 o A dte oe OE ba oma ee RATON odes 24 2 9 TIA ICR 2 Ce ure utra A mcd oer eal ey AS M Toce Ee ar 26 2 32 InsSiebt NIOUE e tii dete Vir eS iS 27 Mark Type Suchen da DU e 29 2 0 c ATIDUTIGEDRO ok genT I pesa AS O A e 30 2 ADC AR AAA DAA A A A ee 31 A gee eR Braap umd ew Gh ar
41. MCB API In this list lower case letters represent numeric values The letters ccc always represent an 8 bit 52 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES unsigned checksum of all characters on the record up to but not including the checksum characters and lt CR gt represents the ASCII carriage return character Axxxcecc lt CR gt xxx is a single 8 bit unsigned number Cxxxxxccc CR XXxxx is a single 16 bit unsigned number Dxxxxxyyyyyccc lt CR gt xxxxx and yyyyy are 16 bit unsigned numbers Exxxxxccc lt CR gt XXxxx is a single 16 bit alarm mask F ssss lt CR gt ssss 18 a variable length ASCII character sequence no checksum is sent with this record Gxxxxxxxxxxccc CR XXXXXXXXXX is a single 32 bit unsigned number IT lt CR gt True response to a SHOW command no checksum IF lt CR gt False response to a SHOW command no checksum Jxxxxxyyyyy ccccCR Response to SHOW CONFIGURATION command Mxxxxxxxxxx ccccCR Response to SHOW STATUS command Nxxxyyyzzzccc lt CR gt XXX yyy and zzz are 8 bit unsigned numbers 4 2 2 MCB Commands This section lists each command with a description of its operation The descriptions include a list of any error codes that may result As described in the two preceding sections the usual response is a macro error code of 0 and a micro error code of 0 no errors Though syntax and communication error responses may result from any command in practice
42. M_CORR CORR_ERR Mode 0 stores the normal and corrected spectra Mode 1 stores the corrected and the error spectra LIST ROI SAMPLE Lists the valid ROI sample settings Response ROI SAMP PUR BLN BLRG BLD BUSY GATE RESV PKDET LIST SHAP CUSP Not used by the DSPEC jr 2 0 included for backward compatibility 59 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 LIST_SHAP_FLAT Lists the valid flattop width settings Response SHAP_FLAT 0 3 2 4 3 24 Settings are 0 3 to 2 4 in 22 steps of 0 1 us LIST_SHAP_RISE Lists the valid rise time settings Response SHAP_RISE 0 8 23 0 4 115 Settings are 0 8 to 23 in 112 steps of 0 2 us LIST_SHUT Lists the valid shutdown settings Response SHUTDOWN TTL ORTEC SMART OFF Turns the DSPEC jr 2 0 off OPEN_FILE filename ext OPEN_FILE_FLASH RESET RESET_REMOTE No function in the DSPEC jr 2 0 included for backward compatibility SET_BLRE baseline This sets the baseline restorer time constant to the value baseline Baseline is in micro seconds with a range from 10 to 100 The specified value is only used if automatic baseline restorer mode is disabled See also ENABLE BLRE DISABLE BLRE and SHOW BLRE SET CORRECTION FLAT value This sets the flattop correction to value The flattop correction is normally determined with the OPTIMIZE command See also SHOW CORRECTION FLAT SET DATA start chans value If the optional start and chans parameters are inc
43. ORTEC DSPEC jr 2 0 Digital Gamma Ray Spectrometer Hardware User s Manual Printed in U S A ORTEC Part No 931010 0914 Manual Revision D Advanced Measurement Technology Inc AMT WARRANTY AMT warrants that the items will be delivered free from defects in material or workmanship AMT makes no other warranties express or implied and specifically NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AMT s exclusive liability is limited to repairing or replacing at AMT s option items found by AMT to be defective in workmanship or materials within one year from the date of delivery AMT s liability on any claim of any kind including negligence loss or damages arising out of connected with or from the performance or breach thereof or from the manufacture sale delivery resale repair or use of any item or services covered by this agreement or purchase order shall in no case exceed the price allocable to the item or service furnished or any part thereof that gives rise to the claim In the event AMT fails to manufacture or deliver items called for in this agreement or purchase order AMT s exclusive liability and buyer s exclusive remedy shall be release of the buyer from the obligation to pay the purchase price In no event shall AMT be liable for special or consequential damages Quality Control Before being approved for shipment each AMT instrument must pass a stringent set of quality control tes
44. OW ZERO ADJUSTMENT command See also SET ZERO ADJUSTMENT ENABLE ZERO STABILIZATION and DISABLE ZERO STABILIZATION LIST BLRE Lists the valid settings of the baseline restore function See also SET BLRE Response BLRE 10 0 100 0 10 100 Legal settings are 10 0 to 100 0 in steps of 1 LIST CORR FLAT Lists the valid settings of the flattop width See also SET CORR FLAT Response CORR FLAT 1 0 992 0 255 Legal settings are from 1 to 0 992 in 255 0 1 256 steps LIST DISPLAY Not used by the DSPEC jr 2 0 included for backward compatibility 58 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES LIST_GAIN_COARSE Lists the valid coarse gain settings Response GAIN_COAR 1 2 4 8 16 32 LIST_GAIN_CONV Lists legal conversion gain settings Response GAIN_CONV 512 1024 2048 4096 8192 16384 LIST_GAIN_FINE Lists the valid fine gain settings Response GAIN_FINE 0 45 1 0 88437 196607 0 45 to 1 in 108171 steps LIST_HV Lists the valid high voltage settings Response HV 0 5000 0 5000 0 to 5000 in 5000 steps LIST_MODE_ZDT Reports the legal ZDT mode settings Each item in the list can be selected by sending the SET_MODE_ZDT command with a mode number The mode number is implied by the loca tion of the mode in the list For example the first item in the list had a mode number of 0 To select the first item send SET MODE ZDT 0 The second item has a mode number of 1 and so on Response MODE_ZDT NOR
45. Off mode when the counting rate is expected to be constant during the time taken to acquire the spectrum e Use the ZDT CORR ERR mode when the counting rate is expected to change or might change significantly during the time required to acquire the spectrum Avoid using the NORM CORR mode because the spectroscopy software will default to analyzing the LTC spectrum and will ignore the ZDT spectrum 1 4 4 3 More Information e Visit our website or contact your ORTEC representative for more detailed information e Application note AN56 Loss Free Counting with Uncertainty Analysis Using ORTEC s Innovative Zero Dead Time Technique http www ortec online com pdf an56 pdf e General gamma spectroscopy technical papers http www ortec online com papers reprints htmZ General 1 5 DSPEC jr 2 0 SMART 1 HPGe Detector Support ORTEC s SMART 1 detector technology is a great advance in the operation of HPGe detectors and is a major enhancement to data and chain of custody integrity The SMART 1 detector has a high voltage supply included so the DSPEC jr 2 0 does not contain a high voltage power 12 931010D 0914 1 INTRODUCTION supply For older detectors a detector interface module DIM is used to supply the HV for the detector The SMART 1 detector monitors and reports on vital system functions Also its identification serial number can be read by a controller such as the DSPEC jr 2 0 For more security it can save authent
46. RMWARE COMMANDS AND RESPONSES SHOW_OVERFLOW_PRESET Reports the state of the overflow preset Responses IT lt CR gt Overflow preset enabled IF lt CR gt Overflow preset disabled SHOW_PEAK This command returns the contents of the ROI channel with the largest number of counts An ROI channel is a channel that has the ROI flag set The maximum possible value is 2147483647 which is the maximum number of counts that can be stored in a 31 bit channel Responses G0000000000075 lt CR gt Maximum count in an ROI channel is zero or no ROI channels were found G0000000001076 lt CR gt Maximum count in an ROI channel is 1 G2147483646120 lt CR gt Maximum count in an ROI channel is 2147483646 G2147483647121 lt CR gt Maximum count in an ROI channel is 2147483647 SHOW_PEAK_CHANNEL This command returns the number of the ROI channel with the largest number of counts An ROI channel is a channel that has the ROI flag set The lowest number ROI channel with the largest count is reported if more that one channel contains the largest number of counts Channel 16383 is the highest numbered channel in any device Responses C00000087 lt CR gt Maximum count was found in channel 0 or no ROI channels were found C00001088 lt CR gt Maximum count was found in channel 1 C16382107 lt CR gt Maximum count was found in channel 16382 C16383108 lt CR gt Maximum count was found in channel 16383 SHOW PEAK PRESET Reports the value of th
47. To use a Sodium Iodide Detector mark the checkbox This changes the gain and zero stabili zers to operate in a faster mode For the DIM 296 the HV is controlled by the adjustment in the Model 296 and not here 33 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 2 3 About This tab Fig 21 displays hardware and firmware information about the currently selected DSPEC jr 2 0 as well as the data Acquisition Start Time and Sample description In addition the Access field shows if the MCB is currently locked with a password see the password discus sion in the MAESTRO user manual Read Write indicates that the MCB is unlocked Read Only means it is locked 2 3 8 Status Figure 22 shows the Status tab There are 21 values monitored at all times You can select any six of these to be displayed simultaneously on the Status tab You would normally pick the six that are most important to you The values you select can be changed at any time so you can view any of them as needed Two types of values are presented OK or ERR and nu meric value The state of health SOH parameters read OK or ERR If the state is OK the parameter stayed within the set limits during the spectrum acquisition If the para meter varied from the nominal value 931010D 0914 a Properties for DSJ2 908 Amplifier Ampifier2 AmpifierPRO ADC Stabilizer High Voltage About Status Presets MDAPreset
48. Y This returns the polarity setting of the input trigger for the sample changer 1 means the trigger is positive edged and triggers on a low to high transition 0 means it is negative edge triggered and triggers on a high to low transition See also TRIGGER ENABLE_ TRIGGER DISABLE_TRIGGER SHOW_TRIGGER and SET_TRIGGER_POLARITY Responses FNEG lt CR gt The HV is set to negative FPOS lt CR gt The HV is set to positive SHOW_TRIGGER_SAMPLE Reports the trigger source in Insight Mode Responses FOLLD LLD is source F1PKD Peak detect is source F2RANDOM Trigger happens randomly F3Gate Gate Input triggers the waveform 83 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SHOW TRIGGER SPECIAL Not used in the DSPEC jr 2 0 included for backward compatibility SHOW TRUE Reports the contents of the true time counter in units of 20 ms 50 ticks s See also CLEAR COUNTERS and SET TRUE Responses G0000000000075 lt CR gt True time reported as O ticks G0000000001076 lt CR gt True time reported as 1 tick 20 ms G4294967295132 lt CR gt True time reported as 4294967295 ticks over 23000 days SHOW_TRUE_PRESET Reports the current true time preset in units of 20 ms 50 ticks s See also CLEAR _ PRESETS and SET_TRUE_PRESET Responses G0000000000075 lt CR gt True time preset reported as disabled G0000000001076 lt CR gt True time preset reported as 1 tick G4294967295132 lt CR gt Tr
49. abilization is currently disabled SHOW_GAIN_WIDTH Reports the current width for the stabilizer gain peak See also SET_GAIN_WIDTH SET_GAIN_CHANNEL and SHOW_GAIN_CHANNEL Responses C00001088 lt CR gt Gain width has not been set C00003089 lt CR gt Gain width is 3 channels lowest possible width C00256100 lt CR gt Gain width is 256 channels highest possible width in Gauss mode SHOW_GATE Reports the current mode of operation of the ADC gate input See also SET_GATE_OFF SET_GATE_COINCIDENT and SET_GATE_ANTICOINCIDENT Responses FOFF lt CR gt Reports the ADC gate is off or ignored FCOI lt CR gt Reports the ADC gate is in coincident mode FANT lt CR gt Reports the ADC gate is in anticoincident mode SHOW_HV Reports the current high voltage and the status of the high voltage power supply in the form Dvvvvvsssssccc 73 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Where vvvvv represents the current output voltage if the high voltage is enabled or the rear panel high voltage setting if the high voltage is disabled sssss represents the status of the high voltage bias supply as a 16 bit decimal number with the following bit definitions Bit 0 LSB Bias supply polarity 0 positive 1 negative Bit 1 Bias supply overload 0 overload 1 normal Bit 2 High voltage enabled 0 disabled 1 enabled Example Responses D0200000003077 lt CR gt 2000 V negative not ove
50. al may exceed the preset value by up to 512 counts due to the pipelined archi tecture of the DSPEC jr 2 0 Setting an integral preset to O counts disables the preset The integral preset may be set to from O disabled to 4294967295 counts See also CLEAR _ PRESETS and SHOW_INTEGRAL_PRESET SET_LENGTH_SAMPLE length Sets the number of points in the Insight mode display to the specified value Normally this setting would remain at 1000 63 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SET LIVE ticks Sets the live time counter to the specified number of ticks The number represents live time in units of 20 ms 50 ticks s Normally this value is set by the DSPEC jr 2 0 during data acquisition See also CLEAR COUNTERS and SHOW LIVE SET LIVE PRESET ticks Sets the live time preset to the specified number of ticks 20 ms tick During data acquisi tion when the live time counter reaches the preset number of ticks the preset is complete and the acquisition is stopped Setting a live time preset to 0 ticks disables the preset See also CLEAR PRESETS and SHOW LIVE PRESET SET LLD chan Sets the lower level discriminator to chan which must be between 0 and 16383 See also SHOW LLD SET MDA COEF a b c Sets the coefficients in the MDA preset calculation to the specified values A b and c are floating point values The MDA preset checks for the following condition to be met at b c CountsinROI MDA Preset g
51. anged 32 931010D 0914 2 GETTING STARTED 2 3 6 High Voltage Figure 20 shows the High Voltage os for DSJ2 908 tab which allows you to turn the high voltage on or off set and monitor the voltage and choose the Shutdown mode Amplifier Ampifier2 AmpifierPRO ADC Stabilizer High Voltage About Status Presets MDAPreset Target O Volts Shutdown Off Actual DO Volts TTL The shutdown can be TTL ORTEC or SMART The ORTEC mode is used for all ORTEC detectors except SMART 1 detectors Use the SMART option for those detectors Check with Off Overload the detector manufacturer for other detectors The TTL mode is used for most non ORTEC detectors Sodium lodide Detector Figure 20 DSPEC jr 2 0 High Voltage Tab The polarity is determined by the DIM or SMART 1 module which also supplies the bias voltage The recommended HV for SMART 1 is displayed on the dialog For other detectors see the detector manual or data sheet for the recommended voltage Enter the detector high voltage in the Target field click On and monitor the voltage in the Actual field Click the Off button to turn off the high voltage The HV will not turn on if the detector is sending a remote shutdown or overload signal The Overload indicator means there 1s a bad connection in your system The Shutdown indicator means that either the detector is warm or you have chosen the wrong Shutdown or Source mode
52. ases the collection time real time of the acquisition to correct for input pulse train losses incurred during acquisition due to system dead time This corrected time value known as the live time is then used to determine the net peak count rates necessary to determine nuclide activities As an example consider the case where the spectrometry amplifier and ADC are 6096 dead during the acquisition the elapsed real time will be DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Real Time 0 60 Live Time _ Live Time x 100 100 Dead Time If the N counts in the gamma ray peak in the spectrum are divided by the elapsed live time the resulting counting rate N Live Time is now corrected for dead time losses The standard deviation in that counting rate is y N Live Time Unfortunately extending the counting time to make up for losses due to system busy results in an incorrect result if the gamma ray flux is changing as a function of time If an isotope with a very short half life is placed in front of the detector the spectrometer might start out with a very high dead time but the isotope will decay during the count and the dead time will be zero by the end of the count If the spectrometer extends the counting time to make up for the lost counts it will no longer be counting the same source as when the losses occurred As a result the number of counts in the peak will not be correct When a sup
53. ates a hazard that could result in bodily harm if the safety instruction is not observed CAUTION Indicates a hazard that could result in property damage if the safety instruction is not observed In addition the following symbols may appear on the product AN DANGER Hazardous voltage N ATTENTION Consult the manual in all cases where this symbol is marked in order to determine the nature of the potential hazards and any actions that must be taken to avoid them QD Protective earth ground terminal Please read all safety instructions carefully and make sure you understand them fully before attempting to use this product Cleaning Instructions To clean the instrument exterior e Disconnect the instrument from the power source e Remove loose dust on the outside of the instrument with a lint free cloth e Remove remaining dirt with a lint free cloth dampened in a general purpose detergent and water solution Do not use abrasive cleaners e Allow the instrument to dry completely before reconnecting it to the power source vii 1 INTRODUCTION The DSPEC jr 2 0 our fifth generation integrated gamma spectrometer based on digital signal processing combines small size the latest in digital signal processing and filters and the fastest data transfer rate available USB 2 0 with the proven performance of the ORTEC DSPEC line of instruments 1 1 Why the DSPEC jr 2 0 New Low Frequency Rejector LFR Filter
54. bsolute maximum width for the gain peak is 256 chan 62 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES nels in Gauss mode In point mode there is no maximum peak width though the chosen width must allow the peak to fit within the device s channel limits as stated above See also SHOW_GAIN_WIDTH SET_GAIN_CHANNEL and SHOW_GAIN_CHANNEL SET_GATE_ANTICOINCIDENT Causes the DSPEC jr 2 0 to use the ADC gate input signal in anticoincident mode See also SET_GATE_OFF SET_GATE_COINCIDENT and SHOW_GATE SET_GATE_COINCIDENT Causes the DSPEC jr 2 0 to use the ADC gate input signal in coincident mode See also SET_GATE_OFF SET_GATE_ANTICOINCIDENT and SHOW_GATE SET_GATE_OFF Causes the DSPEC jr 2 0 to ignore the state of the ADC gate input signal See also SET_ GATE_COINCIDENT SET_GATE_ANTICOINCIDENT and SHOW_GATE SET_HV value This sets the HV bias to value in volts SET_ID id string Sets the sample id string This string can be up to 16 characters long and can be set to any arbitrary value The id string is intended to uniquely identify the sample being analyzed See also SHOW_ID Examples SET_ID Site 123 SET_INTEGRAL_PRESET count Sets the ROI integral preset to the specified count During data acquisition when the sum of the counts contained in the channels that have the ROI flag set reaches the integral preset count the preset is complete and the acquisition is stopped The actual number of counts in the ROI integr
55. but it can be changed on this dialog and in the InSight mode to accommodate particular throughput resolution tradeoffs The optimize feature also automatically adjusts the pole zero setting The dead time per pulse is approximately 3 x Rise Time 2 x Flattop Width 26 931010D 0914 2 GETTING STARTED In the Pole Zero section the Start button performs a pole zero at the specified rise time and other shaping values Unlike the optimize feature it performs a pole zero for only the one rise time The pole zero Stop button aborts the pole zero and is normally not used When you are satisfied with the settings you are ready to acquire data with the Properties dialog open or closed For the more advanced user the InSight mode lets you directly view all the parameters and adjust them interactively while collecting live data To access the InSight mode go to the Insight section on the Amplifier 2 tab and click Start The InSight mode is discussed in more detail in the following section When you are satisfied with the settings you are ready to acquire data Once data acquisition is underway you may wish to return to MCB Properties and click the Insight section s Start button to adjust the shaping parameters interactively with a live waveform showing the actual pulse shape or just to verify that all is well 2 3 2 1 InSight Mode The InSight display Fig 15 shows the actual sampled waveform in the digital processing units
56. command has been included for backward compatibility DISABLE_HV Turns off the high voltage enable signal of the DSPEC jr 2 0 See the section on the bias supply for more information about the high voltage output See also ENABLE_HV and SHOW_HV DISABLE_HV_DIM Disables the use of the Detector connector on the back of the DSPEC jr 2 0 and causes the DSPEC jr 2 0 to suppress State of Health information see SHOW_HV_HEALTH com mand Also the command disables polling of a standard DIM module e g DIM POSNAI DIM POSGE DIM NEGGE or DIM 296 by the DSPEC jr 2 0 DISABLE_LFR Returns the DSPEC jr 2 0 to normal operation if the LFR filter is enabled See also ENABLE_LFR and SHOW_LFR DISABLE_NAI Switches the stabilizers to Ge mode See ENABLE NAI DISABLE OPTI NEED Disables the reporting of an error when the DSPEC jr 2 0 has not been optimized DISABLE OVERFLOW PRESET Disables the overflow preset Channels that receive a count when they contain 2147483647 counts the maximum number of counts will roll over to zero counts if the overflow preset is disabled See also ENABLE OVERFLOW PRESET and SHOW OVERFLOW PRESET DISABLE PZ AUTOMATIC Disables the automatic pole zero mode See also ENABLE PZ AUTOMATIC DISABLE PZ NEED Disables the reporting of an error when the DSPEC jr 2 0 has not been pole zeroed DISABLE REMOTE No function in the DSPEC jr 2 0 included for backward compatibility 55 DSPEC jr 2 0 Digital Gamma Ray Spectromete
57. ction in the DSPEC jr 2 0 included for backward compatibility ENABLE_TRIGGER Enables the Sample Ready connector Acquisition will then start when an external trigger occurs on the Sample Ready connector or when the TRIGGER command is issued See also TRIGGER DISABLE_TRIGGER SHOW_TRIGGER SET_TRIGGER_POLARITY and SHOW_TRIGGER_POLARITY 57 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 ENABLE ZDT Sets the DSPEC jr 2 0 to ZDT mode See SET MODE ZDT for information on selecting the ZDT mode ENABLE ZERO STABILIZATION Enables the stabilization of the zero peak See also DISABLE ZERO STABILIZATION SHOW ZERO STABILIZATION and INITIALIZE ZERO STABILIZATION INITIALIZE Returns the DSPEC jr 2 0 including flash to the factory default settings and simulates a power down power up cycle for the MCB after a simulated loss of battery backed up memory CAUTION Before issuing this command protect the DIM by turning off the detector bias and physically disconnecting the detector cable from the DSPEC jr 2 0 rear panel INITIALIZE GAIN STABILIZATION Resets the gain peak stabilization adjustment to unity no adjustment This value is reported as 2048 by the SHOW GAIN ADJUSTMENT command See also SET GAIN ADJUSTMENT ENABLE GAIN STABILIZATION and DISABLE GAIN STABILIZATION INITIALIZE ZERO STABILIZATION Resets the zero peak stabilization adjustment to unity no adjustment This value is reported as 2048 by the SH
58. ctra mode If a ZDT mode is selected both spectra are stored in the same spectrum SPC file If you do not need the ZDT spectrum you should select Off In MAESTRO the display can show either of the two spectra Use F3 or Acquire ZDT Display Select to toggle the display between the two spectra In the Compare mode F3 switches both spectra to the other type and lt Shift F3 gt switches only the compare spectrum This allows you to make all types of comparisons Conversion Gain This sets the maximum channel number in the spectrum If set to 16384 the energy scale will be divided into 16384 channels The conversion gain is entered in powers of 2 e g 8192 4096 2048 The up down arrow buttons step through the valid settings for the DSPEC jr 2 0 Upper and Lower Level Discriminators The Lower Level Discriminator sets the level of the lowest amplitude pulse that will be stored This level establishes a lower level cutoff by The NORM CORR LTC and ZDT mode is typically not used see Section 1 4 2 31 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 channel number for ADC conversions The Upper Level Discriminator sets the level of the highest amplitude pulse that will be stored This level establishes an upper level cutoff by chan nel number for storage 2 3 5 Stabilizer The Stabilizer tab Fig 19 lets you E for DSJ2 908 adjust and monitor the zero and gain stabilizers which
59. d enabled SHOW_ID Reports the sample ID string as was previously set by the SET_ID command Example Responses FSite 123 lt CR gt ID set to Site 123 FSample 123456789 lt CR gt ID set to Sample 123456789 SHOW_INPUT 0 Reports the state of the Sample Ready input Responses C00000087 lt CR gt Sample Ready input is low C00001088 lt CR gt Sample Ready input is high SHOW INTEGRAL start_chan number_of_chans Reports the sum of the specified group of spectral data channels If start chan and number of chans is not provided SHOW INTEGRAL reports the sum of all channels in the currently selected window that have their ROI flag set Responses G0000000000075 lt CR gt Integral reported as 0 G4294967294131 lt CR gt Integral reported as 4294967294 G4294967295132 lt CR gt Integral reported as greater than or equal to 4294967295 maximum reportable value SHOW_INTEGRAL_PRESET Reports the current ROI integral preset value For more information about the ROI integral preset see SET_INTEGRAL_PRESET See also SHOW_INTEGRAL Responses G0000000000075 lt CR gt Integral preset reported as 0 G4294967295132 lt CR gt Integral reported as 4294967295 SHOW_INTEGRAL_REMAINING Reports the current ROI integral remaining value For more information about the ROI integral remaining see SET_INTEGRAL_REMAINING See also SHOW_INTEGRAL 75 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914
60. d SHOW TRUE PRESET SET ULD value This sets the upper level discriminator to value in channels SET UNCERTAINTY PRESET percent Sets the uncertainty preset to the specified value in percent Percent is a floating point value from 0 99 9999 See also SHOW UNCERTAINTY PRESET SET WINDOW start length Sets the window of interest to the specified start channel and number of channels The chan nels of spectral data in the window of interest are affected by commands such as CLEAR SET DATA and WRITE If neither start nor length is provided the window is set to the maximum size allowed by the conversion gain specified The window of interest is always set to the maximum size after a SET DEVICE command or a SET SEGMENT command SET ZERO ADJUSTMENT value Sets the zero stabilization adjustment to an arbitrary value from 65535 to 65535 The total range of the adjustment value represents 256 channels This adjustment is usually only made by the gain stabilizer and reset to O with the INITIALIZE ZERO STABILIZATION command See also SHOW ZERO ADJUSTMENT SET ZERO CHANNEL chan Sets the center channel for the stabilizer zero peak If a zero channel is chosen such that the beginning channel or ending channel would be below channel 0 or above the maximum 68 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES channel as determined by the conversion gain the zero peak width is reduced until the peak fits the device boundaries A zero channel and w
61. dead time see ZDT mode 1 Zero stabilization uy ERR Eee ea 32 TIM ANAS AAA ed eo bob 32 91 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Intentionally blank 92
62. e Table 2 is a guide to choosing a count rate that will ensure that the most efficient operation of your digital spectrometer over the range of anticipated input count rates for your application that is at or below the throughput peak while achieving the best resolution obtainable from the detector consistent with that requirement Enter the rise time that best matches your dynamic range of count rate note that the available rise time settings will vary by instrument this chart is a general guide only The longest rise time shown in the table is 12 us even though some digital instru Table 2 Rise Time Selection Guide Dynamic Range Throughput a E O eee osa 7 os osa soo os ments can be set for rise times as long as 23 us If throughput is not an issue because all samples are low rate increasing the rise time beyond 12 us might achieve a small improvement in resolu tion For planar detectors such as ORTEC s GLP Si Li IGLET and IGLET X Series operat ing at longer rise times frequently gives improved resolution 2 5 Troubleshooting 2 5 1 MAESTRO Does Not Connect with the DSPEC jr 2 0 If properly installed and functioning MAESTRO software or other CONNECTIONS programs cannot find and communicate with the DSPEC jr 2 0 check for the following e The MCB is not turned on e The USB cable is not properly connected Check the Master Instrument List on the computer to ensure that the DSP
63. e CONNECTIONS Driver Update Kit for complete details on the command line arguments that change how the program searches for MCBs customizing MCB ID Numbers and Descriptions changing your Windows firewall settings to allow MCB access across a network enabling additional device drivers and troubleshooting 1 Make sure the DSPEC jr 2 0 is connected and powered on 2 Connect and power on all other local and network ORTEC instruments that you wish to use as well as their associated computers Otherwise the MCB Configuration program will not detect them during installation Any instruments not detected can be configured at a later time 3 To start the software type mcb in the Search programs and files box on the Windows Start menu then click the MCB Configuration search result or open the Windows Start menu and click MAESTRO then MCB Configuration The MCB Configuration program will locate all of the powered on ORTEC MCBs on the local computer and the network and display the list of instruments found the Master Instrument List Fig 10 If you wish you may enter customized instrument ID numbers and descriptions Section 2 2 4 2 When you close the dialog any changes you have made to an ID number or description will be written back to the corresponding MCB 6 Configure Instruments Version 8 01 Number amp Description Close 1 DSPec 2 DSPec Cancel 3 DS50 00P2U2 MCB 1 4 DS50 11195158 MCB 1 5 DS50 11195158MCB
64. e DIM as delivered to the detector 24 volts This is the current value of the 24 volt supply in the DIM as delivered to the detector High Voltage This is the current value of the high voltage bias supply in the DIM as delivered to the detector Detector temperature This is the detector temperature at the time the current spectrum acquisition stopped This is available only for SMART 1 detectors Live detector temperature This is the detector temperature at the current time This is available only for SMART 1 detectors Battery voltage This is not used in the DSPEC jr 2 0 Battery full This is not used in the DSPEC jr 2 0 Battery time remaining This is not used in the DSPEC jr 2 0 36 931010D 0914 2 GETTING STARTED 2 3 9 Presets Figure 23 shows the Presets tab Properties for DSJ2 908 MDA presets are shown on a Amplifier Ampifier2 AmpifierPRO ADC Stabilizer separate tab High Voltage About Status Presets MDAPreset The presets can only be set on an Real Time s ie a MCB that is not acquiring data Preset in X TM Live Time s during acquisition the preset field E e i art Chan 0 backgrounds are gray indicating that ROI Peak ents ano they are inactive You can use any or all of the presets at one time To EDU C mtem disable a preset enter a value of Overflow zero If you disable all of the presets data acquisition will continue until manually stopped
65. e ROI peak preset See SET PEAK PRESET for information about the ROI peak preset Responses G0000000000075 lt CR gt Peak preset disabled G0000000001076 lt CR gt Peak preset set to 1 count G2147483646120 lt CR gt Peak preset set to 2147483646 counts G2147483647121 lt CR gt Peak preset set to 2147483647 counts 79 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 SHOW_PZ Displays the PZ setting See also SET_PZ Responses PZ_ENA 002200 Pole zero enabled and set to 2200 PZ_DIS 001000 Pole zero disabled and set to 1000 SHOW_PZ AUTOMATIC Shows the state of the automatic PZ See also SET_PZ AUTOMATIC Responses IT lt CR gt Pole zero enabled IF lt CR gt Pole zero disabled TRP SHOW_RADIX SHOW_RATE_ZDT SHOW_REMOTE No function in the DSPEC jr 2 0 included for backward compatibility SHOW_ROI Used in conjunction with the SHOW NEXT command SHOW ROI reports the first contin uous group of channels that have the ROI flag set The response is of the form Dsssssnnnnnccc CR where sssss represents an integer number that is the number of the first channel of the first group of channels that all have their ROI bit set and nnnnn represents an integer number that is the number of channels in the group The SHOW NEXT command is used to report the next group of channels that all have their ROI bit set Responses D0100000050078 CR First ROI group starts at channel 1000 and is 5
66. e Sore ere ee ee eet 11 ADDITIONAL WARRANTY STATEMENT o0cccoccccccnccoco hr iii Safety Instructions and Symbols 23 sc scccesv oes A PERS NM EAT SE MS BOERS aM C RE E vii Cleaning Instr ctlons ao esee see voy e OR CER Ed exe ES e epe p BR RU ais vii Ic ANTRODUCTION np be tinct ad A oce c o Vr Api S ROME Rt t Or e ah e 1 do Wty the DS REC JT 2 07 AA ia ds 1 1 2 The Low Frequency Rejector LFR Filter a AAA dos 3 1 3 Ballistic Deficit and Adjusting the Flattop Duration 00 00005 6 1 4 Zero Dead Time ZDT Mode iste ies vn nd kn Re eee kee RE Can bane ae we kee 7 1 4 1 Off Uncorrected Spectrum Only 0 0 cece eee 9 1 4 2 NORM_CORR ZDT and Uncorrected Spectra Stored 9 1 4 3 CORR ERR ZDT and Error Spectra Stored 0 0 00 000 eae 9 14 4 Choosmeg a Z DT Mod vs on dub etie cr dug Raia ed is 11 1 4 4 1 The NORM_CORR Diagnostic Mode 00055 12 1 4 4 2 To Summarize E dp Sem ee 12 1 4 4 3 More Informations acean dese ER RR ER Cae BERE A Rye E ES PERS 12 1 5 DSPEC jr 2 0 SMART 1 HPGe Detector Support sleeleeeeeesns 12 1 5 1 SMART 1 HPGe Detector Construction oo oooococcoooconoonoooo o 13 125 2 Uso Older Detectors 2255 5r S kee a See a 13 1 5 3 How State of Health SOH is Monitored 0 0 0 00 0000005 14 1 6 Host Computer and Software Requirements 0 00 0 cece ee eee eee 14 1 7 About this AA S eR
67. e is in microseconds ranging from 0 3 to 2 4 in steps of 0 1 See also SHOW SHAP FLAT SET SHAP RISE value Sets the rise time to value Value is in microseconds ranging from 0 8 to 23 0 in steps of 0 2 See also SHOW SHAP RISE 66 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SET SHUTDOWN index Used in conjunction with the LIST SHUTDOWN command to set the high voltage shut down setting Index specifies a position in the list of legal shutdown settings which were displayed with the LIST SHUTDOWN command Example SET SHUT 0 Sets the SHUTDOWN to TTL SET SHUT 1 Sets the SHUTDOWN to ORTEC SET SHUT 2 Sets the SHUTDOWN to SMARTI SET SHUTDOWN ORTEC This sets the bias shutdown mode to ORTEC SET SHUTDOWN SMART Sets the bias shutdown mode to SMART 1 SET SHUTDOWN TTL This sets the bias shutdown mode to TTL SET THRESHOLD NEGATIVE value Sets the negative threshold to value The negative threshold is normally set automatically by the DSPEC jr 2 0 See also ENABLE THRESHOLD AUTOMATIC and SHOW THRESHOLD NEGATIVE SET THRESHOLD POSITIVE value Sets the positive threshold to value The positive threshold is normally set automatically by the DSPEC jr 2 0 See also ENABLE THRESHOLD AUTOMATIC and SHOW THRESHOLD POSITIVE SET TIME hour min sec Sets the time stored in the battery backed up system clock to the specified values hour can be any value from 0 23 min and sec can be any value from 0 59 The current date and time
68. e restorer rate Fast Slow and Auto LLD Digital lower level discriminator set in channels Hard cutoff of data in channels below the LLD setting ULD Digital upper level discriminator set in channels Hard cutoff of data in channels above the ULD setting Ratemeter Monitor the input count rate on the DSPEC jr 2 0 display or computer screen Battery Internal battery backed up memory to maintain settings in the event of a power interruption Presets Multiple presets can be set on any or all of the following e Real Time Stops data collection when the real time reaches this value e Live Time Stops data collection when the live time reaches this value 44 931010D 0914 3 SPECIFICATIONS ROI Integral Integral count stops data collection when the sum of counts in all ROI channels reaches this value ROI Peak Peak count stops data acquisition when the count in any ROI channel reaches this value maximum value of 2 1 counts 2x10 Uncertainty Sets the required statistical accuracy on a key peak for example stop counting when the activity of Co is known to be better than 5 Multi Nuclide MDA Stops data collection when the value of the minimum detectable activity MDA for up to 20 user specified MDA nuclides reaches the needed value The presets are implemented in hardware so the computer does not have to poll the DSPEC jr 2 0 for the preset to operate See Section 2 3 10 for details on the MDA preset calculation
69. e the shaping parameter controls The controls are split into two groups and the other controls button switches between them One group includes Rise Time Flattop Tilt and the Optimize button The Rise Time value is for both the rise and fall times thus changing the rise time has the effect of spreading or nar rowing the quasi trapezoid symmetrically The Flattop controls adjust the top of the quasi trapezoid The Width adjusts the extent of the flattop from 0 3 to 2 4 us The Tilt adjustment varies the flatness of this section slightly The Tilt can be positive or negative Choosing a positive value results in a flattop that slopes down ward choosing a negative value gives an upward slope Alternatively Optimize can set the tilt value automatically This value is normally the best for resolution but it can be changed on this dialog and in the InSight mode to accommodate particular throughput resolution tradeoffs The Optimize button also automatically adjusts the pole zero setting 2 3 3 Amplifier PRO This tab Fig 17 contains the LFR Properties for DSJ2 908 filter control which is discussed in detail in Section 1 2 To enable Low Frequency Rejector mode mark the checkbox Unmark the checkbox to turn off the LFR filter High Voltage About Status Presets MDAPreset Amplifier Ampifier2 AmplfierPRO ADC Stabilizer NOTE You cannot optimize or pole zero the DSPEC jr 2 0 while in LFR mode The Op
70. ent controls including ADC setup parameters acquisition pre sets amplifier gain adjustments pole zero controls and access to the InSight Virtual Oscillo 23 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 scope Just move from tab to tab and set your hardware parameters then click Close it s that easy Note that as you enter characters in the data entry fields the characters will be_underlined until you move to another field or until 5 seconds have lapsed since a character was last entered During the time the entry is underlined no other program or computer on the network can modify this value 2 3 1 Amplifier Figure 13 shows the Amplifier tab Properties for DSJ2 908 This tab contains the controls for a E E uem i age ut atus resets reset Gain Baseline Restore Preampli Amplifier Amplfier2 Amplifier PRO ADC Stablizer fier Type Input Polarity and Optimize Gain 1 00 Baseline Restore Optimize p i 0 25 MO fauo y Start Auto VER A em Stop Auto NOTE Be sure that all of the con EN Preamplifier Type I trols on the tabs have been S 02000 Resistor Feedback v Input Polarity set before clicking the Start Coarse EIE ue Auto optimize button The changes you make on most Count Rate too low for for OPTI property tabs take place immediately There is no cancel or undo for these dialogs Figure 13 DSPEC jr 2 0 Amplifier Tab Gain Set the ampli
71. es the DSPEC jr 2 0 to poll the DIM and causes the DSPEC jr 2 0 to return State of Health information to a controlling program see SHOW_HV_HEALTH command ENABLE_LFR Sets the DSPEC jr 2 0 to LFR mode See also DISABLE_LFR and SHOW_LFR 56 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES ENABLE_NAI Switches the stabilizers to Nal mode The stabilizers use the fine adjustment in Nal mode and the very fine adjustment in Ge mode See DISABLE_NAI ENABLE_OPTI_NEED Enables the reporting of an error when the DSPEC jr 2 0 needs optimizing ENABLE_OVERFLOW_PRESET Enables the overflow preset Channels that receive a count when they contain 2147483647 counts the maximum number of counts will stop the acquisition if the overflow preset is enabled The channel that caused the preset to complete will contain 2147483647 counts See also DISABLE_OVERFLOW_PRESET and SHOW_OVERFLOW_PRESET commands ENABLE_PZ_AUTOMATIC Enables the automatic pole zero mode See also DISABLE_PZ_AUTO and SHOW_PZ_ AUTO ENABLE_PZ_NEED Enables the reporting of an error when the DSPEC jr 2 0 needs pole zeroing ENABLE_REMOTE No function in the DSPEC jr 2 0 included for backward compatibility ENABLE_THRESHOLD_AUTOMATIC Enables automatic determination of the positive and negative thresholds See also DISABLE_THRESHOLD_AUTO SHOW_THRESHOLD_AUTO SET_THRESHOLD_ NEGATIVE and SET_THRESHOLD_POSITIVE ENABLE_THRESHOLD_SAMPLE ENABLE_TRIGGER_SPECIAL No fun
72. et the rise time of the pulses being processed by the digital filter to the minimum value for the resolution needed The pulse rise time and also fall time is based on the time required for each pulse to reach its peak value This peak ing time is about twice that indicated by the conventional time constants displayed on the front panel of commercial analog amplifiers For example germanium detec co o I Throughput cps thousands A c tors are often specified at a 6 us time con 1 5 9 15 20 30 50 75 95 105 120 130 140 stant this setting is equivalent to 12 us Count Rate keps peaking rise time in our digital spectro Figure 25 An Example of the Tradeoff Between meters Throughput and Count Rate Up to some value of rise time one can expect improved resolution with increasing rise time there will however be a tradeoff in maximum throughput to memory Figure 25 illustrates an 40 931010D 0914 2 GETTING STARTED example of this tradeoff ORTEC digital spectrometers operate well above the peak of the throughput curve Operating there allows these instruments to handle an even higher rate of incoming counts but with less data into memory and therefore a longer count time to the same detection limit It is possible to move the peak of the curve to the right more counts to memory with higher input count rate by reducing the pulse rise and fall time thereby trading off reso lution for maximum count rat
73. fier coarse gain by choosing from the Coarse droplist then adjust the Fine gain with the horizontal slider bar or the edit box in the range of 0 45 to 1 00 The resulting effective gain is shown at the top of the Gain section The two controls used together cover the entire range of amplification from 0 45 to 32 Input Polarity These buttons select the preamplifier input signal polarity for the signal from the detector Normally GEM p type detectors have a positive signal and GMX n type have a negative signal Baseline Restore This is used to return the baseline of the pulses to the true zero between incoming pulses This improves the resolution by removing low frequency noise from dc shifts or mains power ac pickup The baseline settings control the time constant of the circuit that returns the baseline to zero There are three fixed choices Auto Fast and Slow The fast set ting is used for high count rates the slow for low count rates Auto adjusts the time constant as appropriate for the input count rate The settings Auto Fast or Slow are saved in the 24 931010D 0914 2 GETTING STARTED DSPEC jr 2 0 even when the power is off The time constant can be manually set on the InSight display see the discussion beginning on page 27 You can view the time when the baseline restorer is active on the InSight display as a Mark region see the discussion on Marks p 29 In the automatic mode the current value is shown on
74. gt Automatic threshold is disabled SHOW_THRESHOLD_NEGATIVE See also SET_THRESHOLD_NEGATIVE Responses THR_NEG 0000379791 Negative threshold is 379791 SHOW THRESHOLD POSITIVE See also SET THRESHOLD POSITIVE Responses THR POS 00000126811 Positive threshold 1s 126811 SHOW TIME Reports the time from the battery backed up system clock in the form Nhhhmmmsssccc lt CR gt 82 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES where hhh represents a 3 digit integer hour 0 23 mmm represents a 3 digit integer minute 0 59 and sss represents a 3 digit integer second 0 59 See also SET_TIME SET_ DATE and SHOW_DATE Example Responses N010054017052 lt CR gt Time returned 10 54 17 10 h 54 min 17 s N020013037050 lt CR gt Time returned 20 13 37 20 h 13 min 37 s SHOW_TIME_START Reports the time of the last START command in the form Nhhhmmmsssccc lt CR gt where hhh represents a 3 digit integer hour 0 through 23 mmm represents a 3 digit integer minute 0 through 59 and sss represents a 3 digit integer second 0 through 59 See also SET_TIME_START SET_DATE_START and SHOW_DATE_START Example Responses N010054017052 lt CR gt Time returned 10 54 17 10 h 54 min 17 s N020013037050 lt CR gt Time returned 20 13 37 20 h 13 min 37 s SHOW_TRIGGER Tells whether the trigger is enabled or disabled See also ENABLE_TRIGGER Responses IF Trigger disabled IT Trigger enabled SHOW_TRIGGER_POLARIT
75. h information as discussed above and in Section 1 5 3 3 Feature Mask Bits The following table describes the feature bits from the SHOW_FEATURES command discussed on page 72 If the feature is supported in the DSPEC jr 2 0 the bit is set to 1 if the feature is not supported the bit is 0 po C RM MM Ld pi o e Ra e e ah eA oN QV tan A WN KF O Meaning Software selectable conversion gain Software selectable coarse gain Software selectable fine gain Gain stabilizer Zero stabilizer PHA mode functions available MCS mode functions available List mode functions available Sample mode functions available Digital Offset e g 920 Software selectable analog offset HV power supply Enhanced HV SET_HV SET SHOW_HV_POL SHOW_HV_ACT Software selectable HV range ENA_NAI DIS NATI Auto PZ START_PZ_AUTO Software selectable manual PZ SET SHOW_PZ Battery backed real time clock SHOW_DATE TIME SHOW_DATE TIME_START Sample changer support SET SHOW_OUTPUT SHOW_INPUT One button acquisition ENA DIS SHOW_TRIG_SPEC MOVE 47 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Bit 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 48 Meaning Nomadic likely to move between opens Local app data SET_DATA_APP SHOW_DATA_APP Software retrievable serial number Power management commands Battery s
76. h parameter SHOW NAI Indicates whether ENABLE NAI has been sent Responses are true and false Responses IT lt CR gt Nal mode enabled IF lt CR gt Nal mode disabled SHOW_NEXT Used in conjunction with the SHOW_ROI command SHOW_NEXT reports the next continuous group of channels that have the ROI flag set The response is of the form Dsssssnnnnncce lt CR gt where sssss represents an integer number that is the number of the first channel of the next group of channels that all have their ROI bit set and nnnnn represents an integer number that is the number of channels in the group If no more channels have their ROI bit set SHOW_NEXT returns a first channel of 0 and a number of channels of 0 The SHOW_ROI command is used to report the first group of channels that all have their ROI bit set Example Responses D0100000050078 lt CR gt Next ROI group starts at channel 1000 and is 50 channels long D0215000150086 lt CR gt Next ROI group starts at channel 2150 and is 150 channels long D0000000000072 lt CR gt No other ROI groups to report SHOW_OUTPUT 0 Reports the status of the Change Sample output port The output port status is reported as a 16 bit number that is O or 1 depending on the level last set by a SET OUTPUT HIGH or SET_OUTPUT_LOW command Responses C00000087 lt CR gt Change Sample output currently low C00001088 lt CR gt Change Sample output currently high 78 931010D 0914 4 FI
77. hat connect the detector to the MCA and provide bias and SMART 1 support if appropriate These modules have an input connector that connects to the DETECTOR connector discussed in Section 3 1 2 On a SMART 1 detector the high voltage module will be hardwired to the detector To support older detectors a detector interface module DIM with 12 inch leads connect the detector and DSPEC jr 2 0 providing HV bias and control The leads are as follows 9 pin D preamplifier power cable Analog In Shutdown In Bias Out Inhibit In The DSPEC jr 2 0 uses the following DIMs e DIM POSGE For any non SMART 1 positive bias HPGe detector includes leads with mating connectors for existing detector cabling 500 V to 5000 V e DIM NEGGE For any non SMART 1 negative bias HPGe detector includes leads with mating connectors for existing detector cabling 500 V to 5000 V 46 931010D 0914 3 SPECIFICATIONS e DIM POSNAI e DIM 296 In all cases except the DIM 296 the bias voltage setting and shutdown polarity are set via photo multiplier tubes 0 V to 1200 kV MAESTRO or other CONNECTIONS software For any positive bias Nal detector includes leads with mating connec tors for existing detector cabling 100 V to 1800V 300 LA For any positive bias Nal detector includes Model 296 ScintiPack tube base preamplifier bias supply for Nal detectors with 14 pin 10 stage The SMART 1 detector provides detector state of healt
78. he MCB is available to accept another pulse 1 e is not busy and is equal to the real time minus the dead time the time the MCB is not available Enter the ROI Peak count preset value in counts With this preset condition the MCB stops counting when any ROI channel reaches this value unless there are no ROIs marked in the MCB in which case that MCB continues counting until the count is manually stopped 37 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 Enter the ROI Integral preset value in counts With this preset condition the MCB stops count ing when the sum of all counts in all channels for this MCB marked with an ROI reaches this value This has no function if no ROIs are marked in the MCB The Uncertainty preset stops acquisition when the statistical or counting uncertainty of a user selected net peak reaches the value you have entered Enter the Preset in value as percent uncertainty at 1 sigma of the net peak area The range is from 99 to 0 1 in 0 1 steps You have complete control over the selected peak region The region must be at least 7 channels wide with 3 channels of background on each side of the peak Note that MAESTRO calculates this preset once per 40 seconds Therefore the software will continue data acquisition up to 40 seconds after the preset has been reached and the uncertainty achieved for a high count rate sample may be lower than the preset value Use the Start Channel and
79. ication codes written to it and report the code at a later time The authentication code value is replaced with every start command At the end of the acquisition both the serial number and code are read and checked with the values at the start of the acquisition ORTEC SMART 1 HPGe detectors monitor the following conditions Preamplifier 24 and 12 V values read only Preamplifier voltage out of range read only Detector element temperature read only Detector high voltage value read only Detector high voltage state on off Detector overload state read only Detector high voltage shutdown state read only Detector serial number read only Detector authentication code read write 1 5 1 SMART 1 HPGe Detector Construction In the SMART 1 detector the controller and high voltage power supply are contained in a single small module and are permanently attached to the detector endcap The cable is strain relieved and sealed This eliminates the possibility that the detector will suffer severe damage from moisture leaking into high voltage connectors The controller can be positioned in any convenient place It does not interfere with shielding or other mounting hardware 1 5 2 Using Older Detectors For older detectors a detector interface module DIM is used The DIM is a compact size and can be attached directly to the detector itself keeping the length of the high voltage cable to the absolute minimum The DIM is only
80. icks SHOW_LLD Shows the lower level discriminator setting See also SET_LLD Responses C00050092 The LLD is 50 SHOW_MDA PeakNumber Reports current MDA for the MDA Preset selected by PeakNumber PeakNumber is assumed to be 0 if not supplied Example response MDA 0000000000010 7 SHOW_MDA_COEF Reports the current settings for coeffficients a b and c used for the MDA calculation See SET MDA COEF Example Responses MDA COEF 000000000002 71 000000000000000 00000021 700001 Coefficient a 2 71 b 0 and c 21 7 SHOW MDA PRESET PeakNumber Reports MDA preset PeakNumber If PeakNumber is omitted 0 is assumed Example Response MDA PRES 0000000000025 7 SHOW MODE Reports the current mode of operation PHA or Sample InSight Virtual Oscilloscope See also SET MODE PHA and SET MODE SAMPLE Responses FPHA lt CR gt PHA mode FSAM lt CR gt Sample mode InSight SHOW_MODE_ZDT Reports the current ZDT mode See SET MODE ZDT Responses MODE ZDT 00000 Mode 0 selected normal and corrected MODE ZDT 00001 Mode 1 selected error and corrected TI DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 SHOW MONI LABEL num Returns with an ASCII string label designation for the state of health parameter for num SHOW MONI MAX Returns with the number of state of health values available for viewing SHOW MONI VALUE num Returns with an ASCII representation of the value for the state of healt
81. ided by the elapsed REAL time to compute the dead time corrected counting rate It is important to note that the standard deviation in the N py counts in a gamma ray peak in the ZDT spectrum is not N Instead the standard devia g yp p ZDT tion is obtained from the Np counts in the same peak ROI in the accompanying error spectrum 11 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 The standard deviation in this case is N pgg And the standard deviation in the computed count ing rate N Real Time is Npgg Live Time 1 4 4 1 The NORM CORR Diagnostic Mode Why is there a NORM CORR mode and why should you avoid using it This mode simultan eously collects the ZDT spectrum and the conventional uncorrected spectrum It is useful for demonstrating that the counts in the uncorrected spectrum divided by the live time is the same counting rate as the counts in the ZDT spectrum divided by the real time in the special case of constant counting rate Because the error spectrum is not collected in NORM CORR mode the standard deviation in the ZDT counts cannot be calculated if the counting rate is varying The spectroscopy software provides some protection for users if the ZDT LTC mode is inadver tently selected In this case the software ignores the ZDT spectrum and presumes you intended to use the uncorrected spectrum in a constant counting rate application 1 4 4 2 To Summarize e Use the ZDT
82. idth must be set before zero stabilization can be enabled See also ENABLE_ZERO_ STABILIZATION SET_ZERO_WIDTH chans Sets the width in channels for the stabilizer zero peak The zero width must be chosen such that the beginning channel is no lower than channel 0 and the ending channel is no higher than the maximum channel as determined by the conversion gain The zero channel and width must be set before zero stabilization can be enabled The absolute minimum width for the zero peak is 3 channels and the absolute maximum width for the zero peak is 256 chan nels in Gauss mode In point mode there is no maximum peak width though the chosen width must allow the peak to fit within the device s channel limits as stated above SHOW_ACTIVE Returns a 1 if the DSPEC jr 2 0 is active 1 e acquiring spectral data or 0 if it is not active Responses C00000087 lt CR gt Not active C00001088 lt CR gt Active SHOW_BLRE Shows the baseline restorer time constant in microseconds See also SET_BLRE Responses BLUE 000000000000091 Time constant is 91 us SHOW BLRE AUTOMATIC Shows whether automatic selection of the baseline restorer constant is off or on Responses IT lt CR gt Automatic baseline is enabled IF lt CR gt Automatic baseline is disabled SHOW_CONFIGURATION Returns a record that indicates the hardware configuration of the MCB The record contains information about the number of segments in an MCB device always 1 for the DSPE
83. ings osas 24 26 anticoincidence ara 31 COMCIGENCS cem Codes uen t S ds 3l high voltage setup ss iaa ee eb 33 MSieht mode nso te Rebus 27 a Ga beg pe mt COS eb eyes 37 low frequency rejector LFR 3 30 lower level discriminator 31 MDA DieSeb us cabins Gata ay tel bes 38 A sent ap ene ea oa 25 o rosse t a DE ee Cb 38 Teal nrre Presea rali obe eben 37 ROI integral presets co ee bs 38 ROI peak count preset o oo 37 stabilizer SUID eicit aa Ras a 32 uncertainty preset arado 38 upper level discriminator 32 zero dead time ZDT mode 31 beate mask Dlls 6 o3 scere to SR Es 47 A ntan a a e 26 ballistic deficiti a o 6 95 oa ese eb ees 6 TATUS nios o e bea S DC A PS 26 Wa eese cyt a DE NA RSS 26 Gain stabilization susce ta Bese Cab a 32 A a COS bc 32 Hish volldBe 6 hbk SOS es 33 InsiehtModer seria aia 26 27 Mark TYPOS esan bib cup t CS US scs 29 TnstallanOn56 osos orb oo t SESS RSS 19 Integratoti UME 2osoiba ee talas 26 Low Frequency Rejector LFR 3 Lower level discriminator LLD 31 MDA pr s t hob a bats COPS bo 38 Presets see Acquisition presets 37 Resol tion a td eae 26 SMART 1 detector 1 12 17 34 State of health SOH 2 14 34 89 Troubleshooting cui a dea 41 Uncertainty Preset bash od Seder ben een 38 Upper level discriminator ULD 32 ZDT Modo cabra eme bes 1 7 31 zero
84. ish them from mandatory parameters e g SET_WINDOW start length Com mands with optional parameters can be sent to the MCB without the optional parameters in which case the instrument behavior will be explained in the command description 4 2 Error Codes On each completion of the command the MCB returns a macro error code and micro error code The macro error code represents the general class of error with O meaning no error and the micro error code represents the sub class of error with O meaning no error In case of error condition you can use the MIOGetLastError DLL interface or GetErrMajor GetErrMinor ActiveX control interface Macro error codes 0 Success ss Power up just occurred Battery backed data lost 51 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 i 132 Invalid Command For macro code 129 syntax error or 131 execution error the following apply 129 Micro error codes Success Input already started stopped 2 Preset already exceeded Input not started stopped Parameter was rounded for decimal numbers No sample data available 4 2 1 Dollar Response Records SHOW and STEP commands respond with a single dollar response record followed immediately by a percent response record All valid dollar response records for each command are listed in the command dictionary The following list provides the general form of each dollar response record for the
85. lse is there 27 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 The Delay setting is the time delay between the pulse shown on the display and the trigger level crossing The value of the time delay is shown on the display eet InSight DSJ2 005 Calibration source 1714 File Acquire Calculate Services ROI Display sal eD 21 tool A 2 92 61 0002 oun 005 z Mark Peak m Trigger LLD Single Reset Delay 7360 Baseline Restorer Auto E8 nS Fast C C Slow up o 4i Pole Zero Auto 2064 4 Other Controls ORTEC 11 00 45 AM wed 10 Jul 02 m Mcb Model No DSJ2 002 Figure 15 DSPEC jr 2 0 InSight Mode Just as for the PHA mode display the vertical scale can be adjusted with the vertical adjust ments The display can be set to Log mode but the peak shapes do not have a familiar shape in this display The Auto mode will adjust the vertical scale for each pulse The pulse is shown before the amplifier gain has been applied so the relation between channel number and pulse height is not fixed The horizontal scale extends from 16 to 256 channels The display is expanded around the marker position which means that in some cases the peak will disappear from the display when it is expanded The display can be switched from the DSPEC jr 2 0 to another detector or the buffer In this case the other detector will be shown in the mode selected for it The
86. luded in this command the range of chan nels specified by start and chans is loaded with value If start and chans are not specified sets all channels of spectral data in the window of interest see SET WINDOW command to the specified value ROI flags are not affected 60 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SET DATA APPLICATION stringl string2 This is used to store information in the DSPEC jr 2 0 internal memory that can be used by other programs such as sample descriptions and energy calibrations CONNECTIONS uses this feature String the data identifier 32 bytes maximum string2 the data 128 bytes maximum SET DATE day month year Sets the date stored in the battery backed up system clock to the specified values Day can be any value from 1 31 month any value from 1 12 and year any value from 0 99 The cur rent date and time are stored for a device when an acquisition is started See also SHOW DATE SET TIME and SHOW TIME SET DATE START day month year Sets the start date to the specified values Normally the start date and time are set automati cally whenever a device is started with the START command See also SHOW DATE START SET TIME START and SHOW TIME START SET DELAY COLLECTION value Controls the pileup rejector by setting a width threshold such that if a fast channel discrimi nator pulse is wider than value the pulse is rejected This portion of the pileup rejector rejects pulses that a
87. minator has been triggered Typically this signal only marks the TRP reset pulse The signal is used internally in the live time correction baseline restoration and pile up rejection circuits BaseLineR This shows when the baseline restorer is actively restoring the baseline PosBLDisc This shows when the positive baseline discriminator has been triggered The signal is used internally in the live time correction baseline restoration and pile up rejection circuits Busy When the DSPEC jr 2 0 busy signal is active Busy shows in the Mark box It represents the dead time Gate This shows when the gate signal is present on the gate input connector If the Gate mode on the ADC tab see Fig 18 is set to Off then all regions are marked If the mode is set to Coincidence then the marked region must overlap the pulse peak that is must start before the beginning of the flattop 29 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 and stop after the end of the flattop for the pulse to be counted If the mode is set to Anticoincidence then the marked region will show the pulses that are accepted That is the rejected peaks will not be marked Simply put in all modes the accepted peaks are marked Peak This is the peak detect pulse It indicates when the peak detect circuit has detected a valid pulse The Mark occurs about 1 5 us after the pulse maximum on the display On the lower right of the InSight display ar
88. mputers to use this computer s instruments M Figure 9 Choose USB based instruments If you also have other types of MCBs attached to this computer refer to the installation instruc tions in the corresponding hardware manuals Note that you can install device drivers for other types of instruments later as described in the CONNECTIONS Driver Update Kit instructions 2 2 2 Step 2 Install MAESTRO Install MAESTRO according to the instructions in its User Manual 2 2 3 Step 3 Connect the DSPEC jr 2 0 to the Computer 1 With the computer powered on connect the DSPEC jr 2 0 to the computer s USB port 2 Windows will indicate that the DSPEC jr 2 0 has been detected In Windows 8 and 7 the driver will install without a wizard In XP the new hardware installation wizard will open Click Next indicate you do not wish to connect to the internet or the Microsoft website to locate the driver choose the automatically locate driver option and follow the remaining prompts to completion When this operation is complete you are ready to run the MCB Configuration program so that MAESTRO and other CONNECTIONS software can recognize the DSPEC jr 2 0 20 931010D 0914 2 GETTING STARTED 2 2 4 Step 4 Run MCB Configuration to Communicate With Your MCBs IMPORTANT This is an abbreviated discussion of the operation and use of the MCB Configuration program We strongly recommend that you read the instructions for th
89. n O to power down or ON OFF 5 to ignore the shutdown command This is shown on the display Backlight button Press to turn the display backlight on and off 2 1 2 Rear Panel Figure 8 shows the rear panel The DSPEC jr 2 0 uses an ac dc adapter Connect the power supply unit to the instrument s 12 15 V DC connector Attach the SMART 1 HPGe detector or DIM cable to the DETECTOR connector 18 931010D 0914 2 GETTING STARTED WARNING ORTEC DSPEC jr 2 0 NO USER SERVICEABLE PARTS OPENING CASE VOIDS WARRANTY U S A PATENTS RS 232 MADE IN USA 5 821 533 12 15 V DC 5 872 363 le a amp G Ol USB 5 912 825 6 327 549 MAX PWR 18W DETECTOR C A CE Figure 8 DSPEC jr 2 0 Rear Panel Finally connect the USB port to the computer Note that you can connect to and disconnect from the computer without restarting Windows or MAESTRO 2 2 Software and Hardware Installation Installing the DSPEC Jr 2 0 and the MAESTRO MCA Emulation Software takes just four easy steps You must have Administrator access in Windows to install MAESTRO For easiest installation do not connect the DSPEC Jr 2 0 to your computer until MAESTRO has been installed 1 Install the accompanying CONNECTIONS Driver Update Kit P N 797230 selecting the USB based instruments family on the install wizard s Instrument Setup page 2 Install the accompanying MAESTRO MCA Emulation Software A65 BW 3 Connect the DSPEC Jr 2 0 to
90. needed for non SMART 1 detector use The DSPEC jr 2 0 uses the following DIMs for support of non SMART 1 detector systems e DIM POSGE For any non SMART 1 positive bias HPGe detector includes short leads with mating connectors for connecting to existing detector cabling 500 V to 5000 V 13 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 e DIM NEGGE For any non SMART 1 negative bias HPGe detector includes short leads with mating connectors for connecting to existing detector cabling 500 V to 5000 V e DIM POSNAI For any positive bias Nal detector includes short leads with mating connectors for connecting to existing detector cabling 100 V to 1800 V e DIM 296 For any positive bias Nal detector with Model 296 ScintiPack tube base preamplifier bias supply for Nal detectors with 14 pin 10 stage photo multiplier tubes 0 V to 1200 kV 1 5 3 How State of Health SOH is Monitored The SMART 1 HPGe detector SOH function operates as follows When the acquisition is started the DSPEC Pro clears all the bits of the SOH byte in the SMART 1 HPGe Detector memory During data acquisition the SMART 1 HPGe Detector monitors the conditions listed above Should any of these values fall outside a specified range even if they subsequently return to normal the relevant SOH bit is set The bits stay set until cleared externally with the Acquire Clear command in MAESTRO or the firmware commands CLEAR CLE
91. nt and automatic baseline restorer Patent number 5 872 363 Patent number 5 912 825 2 931010D 0914 1 INTRODUCTION e Highly accurate Gedcke Hale extended live time correction method 1 2 The Low Frequency Rejector LFR Filter In designing an MCB that can be used in conjunction with mechanical coolers ORTEC has developed a new digital filter the Low Frequency Rejector LFR filter capable of correcting the pulse output signal for change in the baseline caused by cooler induced microphonics In many ways digital filters are easier to understand than their analog counterparts Figure 1 shows the voltage step output produced at the preamplifier by the collection of charge produced by absorption of a gamma ray and the resulting trapezoidal weighting function in a digital spectro meter The difficulty in the measurement is to precisely determine the height of the step pulse because the baseline contains noise A fairly obvious estimate of the step signal is obtained by averaging the digitized samples of the signal before and after the step M samples immediately after the event are first ignored to allow for a maximum rise time of M times the sample inter val N samples of the baseline prior to the step pulse are averaged and then subtracted from the average of N samples taken after the step pulse This simple procedure produces a trapezoidal weighting function with a rise time of N sample intervals and a flat top of M sample i
92. ntervals The maximum value of the trapezoid output occurring at the end of the flat top is the best estimate of the step height and therefore the gamma ray energy With a proper selection of M and N this filter is very nearly the optimum filter for a system with noise arising only from the detector leakage parallel noise and the FET current series noise The trapezoidal filter is essentially M N independent of dc offsets since the averaging and subtracting removes the dc component of the signal Unfortun ately it is just as sensitive as analog filters to slowly varying signals such as those produced in microphonic noise N N N Figure 1 shows the output of the trape Figure 1 Typical Trapezoidal Weighting Function zoidal filter is equal to the slope of the i A A bathe tall right Arising from Detector Preamplifier Output 8 P y Signal left width at half maximum FWHM of the trapezoid If a step pulse were to be measured on such a baseline the filter output value would be too great by an error equal to the difference between the average values A1 and A2 Since the microphonic noise component in a signal is approximately a sine wave as illustrated in Fig 2 Ron Jenkins R W Gould and Dale Gedcke Quantitative X Ray Spectrometry New York Marcel Dekker Inc 1981 pp 266 267 Patent pending DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 the error induced can be po
93. or are the presets changed CLEAR HV HEALTH Clears resets the state of health bits This command clears the SOH bits in the DIM and does not affect the stored SOH which is reported when the instrument is not acquiring data CLEAR MDA PRESET Clears all MDA preset values This command is used to quickly clear the list of MDA preset values CLEAR PRESETS The live time true time ROI integral ROI peak and overflow presets are all set to zero disabled CLEAR ROI The region of interest flags for the channels in the window of interest see SET WINDOW command in the currently selected device see SET DEVICE command are cleared CLOSE FILE FLASH crc No function in the DSPEC jr 2 0 included for backward compatibility COMP No function in the DSPEC jr 2 0 included for backward compatibility DISABLE BLRE AUTOMATIC Disables the automatic determination of baseline restorer time constant See also ENABLE BLRE AUTOMATIC SET BLRE and SHOW BLRE DISABLE GAIN STABILIZATION Stops stabilization of the gain peak while data is being acquired The gain stabilization adjustment is held at its current value until either gain stabilization is reenabled with the ENABLE GAIN STABILIZATION command or reinitialized with the INITIALIZE _ 54 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES GAIN_STABILIZATION SET_GAIN_PEAK or SET_GAIN_WIDTH command See also SHOW_GAIN_STABILIZATION DISABLE_GATE_ROUTE No function in the DSPEC jr 2 0 This
94. ported ORTEC MCB operates in ZDT mode it adjusts for the dead time losses by taking very short acquisitions and applying a correction in real time that is as the data are coming in to the number of counts in the spectrum This technique allows the gamma ray flux to change while the acquisition is in progress yet the total counts recorded in each of the peaks are correct The resulting spectrum has no dead time at all in ZDT mode the data are correc ted not the acquisition time Thus the net counts in a peak are divided by the real time to deter mine the count rate ZDT mode has a unique feature in that it can store both the corrected spectrum and the uncor rected spectrum or the corrected spectrum and the uncertainty spectrum Therefore supported MCBs allow you to choose between three ZDT Mode settings on the ADC tab under MCB Properties Off NORM_CORR and CORR_ERR Table 1 shows which spectra are collected in the three possible ZDT modes Patent number 6 327 549 8 931010D 0914 1 INTRODUCTION Table 1 ZDT Modes Uncorrected ZDT Corrected ZDT Error Spectrum Spectrum Spectrum Off ZDT Disabled NORM_CORR ZDT LTC Mode CORR ERR ZDT ERR Mode 1 4 1 Off Uncorrected Spectrum Only In this mode only the uncorrected spectrum live time and real time with dead time losses also called the live time corrected or LTC spectrum is collected and stored in the SPC file The LTC spectrum can be
95. previous SET DATA APPLICATION command then string2 from that command is returned The response is a F record SHOW_DATE Returns the day month and year of the current date as maintained in the battery backed up real time clock in the form dddmmmyyy The day is returned as a 3 digit integer number from 001 to 031 month as a 3 digit integer number from 001 to 012 and year as a 3 digit integer number from 000 to 099 See also SET_DATE_START Responses N001001088052 lt CR gt Date reported as Jan 1 1988 N031012099059 lt CR gt Date reported as Dec 31 1999 N001001000036 lt CR gt Date reported as Jan 1 2000 N031012087056 lt CR gt Date reported as Dec 31 2087 70 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SHOW_DATE_START Returns the day month and year of the acquisition start date in the form dddmmmyyy The day is returned as a 3 digit integer number from 001 031 month as a 3 digit integer number from 001 012 and year as a 3 digit integer number from 000 099 See also SET_DATE_ START Responses N001001088052 lt CR gt Date reported as Jan 1 1988 N031012099059 lt CR gt Date reported as Dec 31 1999 N001001000036 lt CR gt Date reported as Jan 1 2000 N031012087056 lt CR gt Date reported as Dec 31 2087 SHOW_DELAY_COLLECTION Shows the width of the PUR signal setting See also SET DELAY COLLECTION Responses DEL_COLL 0000000000001 6 SHOW_DELAY_SAMPLE Shows the Delay Sample setting See al
96. r 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 10 0 1 0 01 M 0 K w 3 1x10 1x10 1x10 1x10 1x107 1x107 0 01 0 1 l 4 w in MH Frequency in MHz 2 Figure 4 Theoretical Output of Typical dashed line and LFR solid line Weighting Functions Using 10 microsecond Rise Times 1 3 Ballistic Deficit and Adjusting the Flattop Duration In germanium detectors it takes a variable amount of time to collect all of the charge released in the detector diode when a gamma ray deposits energy in the detector The duration of this charge collection time depends on the dimensions of the detector the geometry of the electrodes and the points at which energy is deposited in the detector A small planar detector has charge col lection times that vary from 50 ns to 100 ns whereas a large coaxial detector is characterized by charge collection times that vary from 100 ns to 700 ns The variability of the charge collection time within a specific detector is the source of the resolution degradation described by the ballistic deficit effect The ballistic deficit becomes a significant source of resolution degradation when very short shaping times are selected in order to reduce dead time and improve the high counting rate limit For a digital filter having the shape of a symmetrical triangle in the time domain the output pulse begins to rise as soon as the gamma ray is detected It continues to rise
97. r User s Manual 951010D 0914 DISABLE THRESHOLD AUTOMATIC DISABLE THRESHOLD SAMPLE DISABLE TRIGGER SPECIAL No function in the DSPEC jr 2 0 included for backward compatibility DISABLE TRIGGER Disables the data acquisition trigger that was enabled by the ENABLE TRIGGER com mand Cancels an ENABLE TRIGGER REP if it is issued before the acquisition starts See ENABLE TRIGGER TRIGGER and SHOW TRIGGER DISABLE ZERO STABILIZATION Stops stabilization of the zero peak while data is being acquired The zero stabilization adjustment is held at its current value until either zero stabilization is reenabled with the ENABLE ZERO STABILIZATION command or reinitialized with the INITIALIZE _ ZERO STABILIZATION SET ZERO CHANNEL or SET ZERO WIDTH commands See also SHOW ZERO STABILIZATION DISABLE ZDT Returns the DSPEC jr 2 0 to normal operation if in zero dead time ZDT mode See ENABLE ZDT ENABLE BLRE AUTOMATIC Enables the automatic determination of baseline restorer time constant See also DISABLE _ BLRE AUTO SHOW BLRE and SET BLRE ENABLE GAIN STABILIZATION Enables the stabilization of the gain peak See also DISABLE GAIN STABILIZATION SHOW GAIN STABILIZATION and INITIALIZE GAIN STABILIZATION ENABLE HV Turns on the high voltage enable output of the DSPEC jr 2 0 See also DISABLE HV and SHOW HV ENABLE HV DIM Enables the DSPEC jr 2 0 to work with a standard DIM e g DIM POSNAI DIM POSGE or DIM NEGGE DIM 296 This command enabl
98. re too close together to be detected separately by the fast channel Value is in microseconds with a range from 0 250 to 1 6 in steps of 0 05 See also SHOW _ DELAY COLLECTION SET DELAY SAMPLE num Delays the waveform collected in InSight mode by num points Num must be between O and 65535 See also SHOW DELAY SAMPLE SET DEVICE SET DISPLAY SET FRONT BYPASS No function in the DSPEC jr 2 0 included for backward compatibility SET GAIN ADJUSTMENT value Sets the gain stabilization adjustment to an arbitrary value from 65535 to 65535 This adjustment is usually made only by the gain stabilizer and reset to O with the INITIALIZE _ GAIN STABILIZATION command See also SHOW GAIN ADJUSTMENT SET GAIN CHANNEL chan Sets the center channel for the stabilizer gain peak If a gain channel is chosen such that the beginning channel or ending channel would be below channel 0 or above the maximum 61 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 channel as determined by the conversion gain the gain peak width is reduced until the peak fits the device boundaries A gain channel and width must be set before gain stabilization can be enabled SET GAIN COARSE num This sets the coarse gain to num which must be 1 2 4 8 16 or 32 See also SHOW _ GAIN COARSE SET GAIN CONVERSION chans Sets the conversion gain The conversion gain defines the number of channels within the device that will used for spectral data This
99. rloaded disabled D0200000002076 lt CR gt 2000 V positive not overloaded disabled D0200000007082 lt CR gt 2000 V negative not overloaded enabled SHOW_HV_ACTUAL Returns the value of HV actually on the detector SHOW_HV_DIM Indicates whether HV_DIM is enabled or disabled SHOW_HV_HEALTH Returns the status of the state of health for the detector as reported by the DIM or SMART 1 SHOW_HV_POLARITY This returns the HV polarity defined in the DIM as a F record Responses FNEG lt CR gt The HV is set to negative FPOS lt CR gt The HV is set to positive SHOW_HV_RECOMMEND Returns HV in volts in ASCII from SMART 1 detectors SHOW_HV_TARGET Under normal operation the HV will go to this value when the HV is enabled Reports the current HV setting see SET_HV and the status of the HV power supply in the form DvvvvvsssssccccCR where vvvvv represents the HV setting and sssss represents the status of the HV bias supply as a 16 bit decimal number with the following bit definitions Bit 0 LSB Bias supply polarity 0 positive 1 negative Bit 1 Bias supply overload 0 overload 1 normal Bit 2 HV enabled 0 disabled 1 enabled 74 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES Example Responses D0200000003077 lt CR gt 2000 V negative not overloaded disabled D0200000002076 lt CR gt 2000 V positive not overloaded disabled D0200000007082 lt CR gt 2000 V negative not overloade
100. rrection 39 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 931010D 0914 To add an MDA preset enter the preset value in the MDA or Correction field select the Nuclide and Energy enter the desired values for coefficients a b and c then click Add New To edit an existing preset click to highlight it in the table This will load its Nuclide Energy and coefficients in the lower sections of the dialog Change as needed then click Update To remove a preset click to highlight it in the table then click Delete IMPORTANT These MDA presets are not dynamically calculated Each time you add an MDA preset to this table its CorrectionFactor value is calculated and stored in the MCB s memory If you then load a different library change the efficiency calibration or change the system geometry the spectroscopy application will not update the existing CorrectionFactors and your MDA presets may no longer be applicable When using spectrum analysis applications such as GammaVision and Scinti Vision you can create an analysis options file SDF or SVD file for each system geometry that you use and include in it a set of MDA presets specific to that geometry efficiency calibration and nuclide library You can then recall this tailored analysis options file as needed 2 4 Setting the Rise Time in Digital MCBs To achieve the best results when using a digital spectrometer such as the DSPEC jr 2 0 we recommend that you s
101. rse gain is returned in terms of an integer gain multiplier Responses C00001088 lt CR gt Coarse gain reported as 1 C00002089 lt CR gt Coarse gain reported as 2 C00004091 lt CR gt Coarse gain reported as 4 C00008095 lt CR gt Coarse gain reported as 8 C00016094 lt CR gt Coarse gain reported as 16 C00032092 lt CR gt Coarse gain reported as 32 SHOW_GAIN_CONVERSION 72 This command returns the conversion gain Responses C00512095 lt CR gt Conversion gain reported as 512 channels C01024094 lt CR gt Conversion gain reported as 1024 channels C02048101 lt CR gt Conversion gain reported as 2048 channels C04096106 lt CR gt Conversion gain reported as 4096 channels C08192107 lt CR gt Conversion gain reported as 8192 channels C16384109 lt CR gt Conversion gain reported as 16384 channels 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SHOW_GAIN_FINE Returns the current fine gain setting See SET_GAIN_FINE Sample Response GAIN_FINE 000000 70000203 Fine gain is set to 0 7 SHOW_GAIN_ POLARITY Returns the polarity of the amplifier input as F records Responses FNEG lt CR gt The amplifier input is set to negative FPOS lt CR gt The amplifier input is set to positive SHOW_GAIN_STABILIZATION Reports the state of gain peak stabilization See also ENABLE_GAIN_STABILIZATION and DISABLE_GAIN_STABILIZATION Responses IT lt CR gt Gain stabilization is currently enabled IF lt CR gt Gain st
102. s necessary to accept higher counting rates the rise fall times must be shortened accordingly For this case the DSPEC jr 2 0 includes a flattop feature for the filter that can eliminate the resolu tion broadening caused by ballistic deficit Instead of a symmetrical triangle with a sharp point at the peak amplitude the rising and falling edges are separated by a flattop to form a trapezoid The width of the flattop is adjusted to be long enough to match the longest charge collection time for the detector employed This allows time for the longer charge collection pulses to reach the same maximum pulse amplitude as the faster charge collection pulses from gamma rays of the same energy Consequently the ballistic deficit is eliminated and the energy resolution is dramatically improved at these short pulse widths Note that the selection of shorter pulse widths inevitably degrades the signal to noise ratio com pared to the optimum achieved at longer pulse widths Thus operating at shorter pulse widths will compromise the energy resolution of low energy gamma rays for which the preamplifier noise makes a significant contribution to the energy resolution The signal to noise degradation is independent of the ballistic deficit effect The flattop and other shaping controls are on the Amplifier 2 tab under Acquire MCB Proper ties see Section 2 3 2 for a more detailed discussion 1 4 Zero Dead Time ZDT Mode An extended live time clock incre
103. ser manual If a modified description has already been applied to a particular instrument you can restore the default description by deleting the entry in the Description field and re running MCB Config uration After MCB Configuration runs the default description will be displayed 2 2 5 Attaching More Than One DSPEC jr 2 0 to the Computer Once the drivers have been installed for one DSPEC jr 2 0 adding subsequent units is simple REMINDER Be sure to run MCB Configuration any time you add new DSPEC jr 2 0s or other ORTEC MCBs to your system or when you move an instrument from one USB port to another 2 2 6 Connecting to and Disconnecting from the Computer The USB connection allows you to connect DSPEC jr 2 0s to and disconnect them from a USB port without shutting down the computer or USB hub Note that if MAESTRO is running when you disconnect the DSPEC jr 2 0 you will see a detector not responding message on the status line at the bottom of the MAESTRO window When you reconnect the DSPEC jr 2 0 to the com puter you will have to reselect it from the detector droplist on the Toolbar 2 3 DSPEC jr 2 0 MCB Properties in MAESTRO This section discusses the hardware setup dialog you will see within MAESTRO and all other ORTEC CONNECTIONS software e g GammaVision ISOTOPIC when you click Acquire MCB Properties The DSPEC jr 2 0 is completely software controlled the MCB Properties dialog contains all of the instrum
104. sitive negative or zero This error signal adds to the width of the spectral lines appearing as degraded resolution performance from the detector and can in many cases be a dominant noise source especially at lower energies The ORTEC LFR filter removes most of the microphonic noise by estimating the microphonic induced error signal on a pulse by pulse basis and subtracting the estimated error signal from the trapezoid output As noted above the error signal is proportional to the slope of the baseline during the energy mea surement If the slope is known then so is the error introduced by the micro phonics An excellent estimate of the slope can be obtained by using the trapezoidal filter itself to measure the slope both before and after the energy measurement Since the digital filter is always sampling the input signal it is only necessary to store 1 the values measured before the event is detected 2 the gamma ray energy measurement and 3 the values measured after the event is detected The modified trape zoidal digital filter for LFR from an InSight Virtual Oscilloscope trace is shown in Fig 3 A suitably weighted and averaged value of the before and after slope measurement is then subtracted from the energy measurement producing a measurement essentially free of microphonic noise Although the inherent increase in the pulse processing time increases the dead time of the system the resolu tion can be greatly enhanced
105. so SET_DELAY_SAMPLE Responses C00003090 The sample number is 00003 and 090 is the checksum SHOW_DET_SNUM This command responds with the detector serial number stored in the SMART 1 DIM Response FP40175 Serial number P40175 SHOW_DET_VERSION Returns the DIM firmware version Examples FNAIDO00 Nal DIM firmware version FSMDT000 SMART 1 firmware version SHOW_DEVICE Shows the currently selected device Always 1 for DSPEC jr 2 0 SHOW_DISPLAY Not used included for backward compatibility 71 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SHOW FEATURES Responds with four 32 bit masks indicating which features are present in the MCB See Appendix 3 3 for a complete description of each bit in the mask Example Response FEATURES 02285062207 02014941185 00000000000 00000000000 SHOW GAIN ADJUST Returns the gain stabilizer amplifier setting SHOW GAIN CHANNEL Reports the current center channel for the stabilizer gain peak See also SET GAIN CHANNEL Responses C00000087 CR Gain channel has not been set C00002089 CR Gain channel is channel 2 lowest possible channel C16382107 CR Gain channel is channel 16382 highest possible channel SHOW GAIN COARSE Returns the coarse gain for the DSPEC jr 2 0 internal amplifier In operation the resulting signal gain is the product of the coarse gain the fine gain and the super fine gain used by stabilizer The coa
106. t Live Time The calculation is performed once every 30 seconds with i starting at 0 and advancing through each of up to 20 unique MDA presets i only advances once the preset has been met Note that a b and c are the same for each of the unique presets Only the ROI range and the MDA preset change when i advances Once i reaches 20 or MDAPreset equals 0 the acquisition terminates SET MDA PRESET MDAPreset PeakNumber Sets the MDAPreset PeakNumber value as shown in the equation in the SET MDA COEF description above MDAPreset is usually the product of the desired MDA the yield and the efficiency PeakNumber is a parameter that specifies which of up to 20 0 19 MDA presets to change If PeakNumber is omitted in the set command all MDA preset values will be set to 0 disabled and the supplied value will be applied to MDA Preset 0 This provides com patibility software that only supports the one nuclide MDA method implemented in some MCBs SET MODE PHA Sets the mode to PHA 64 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SET_MODE_SAMPLE Starts the InSight Virtual Oscilloscope mode SET_MODE_ZDT mode Sets the ZDT mode LIST MODE ZDT can be used to determine which modes are valid Mode 0 standard indicates that a normal and corrected spectrum should be stored Mode 1 enhanced indicates that an error and a corrected spectrum should be stored ENABLE ZDT must be issued to turn on ZDT mode SET OUTPUT port
107. tatus support SHOW_STAT_BATT Software selectable AMP polarity SET SHOW_GAIN_POLAR Support for flattop optimization ENA DIS_OPTID Stoppable AutoPZ STOP_PZ_AUTO Network support e g DSPEC Multi drop serial support e g MicroNOMAD Software selectable DPM address SET_DPM_ADDR Multiple devices e g 919 Software selectable ADC gate mode SET_GATE Software downloadable firmware Time histogramming functions available e g 9308 Software selectable lower level discriminator Software selectable upper level discriminator MCS mode SCA input available MCS mode positive TTL input available MCS mode fast negative NIM input available MCS mode discriminator input available Software switchable MCS mode discriminator edge Software programmable MCS mode discriminator level Software programmable SCA upper and lower thresholds Software selectable MCS mode input sources Uncertainty statistical preset SET_UNCERT_PRES Features vary by input SHOW_FEATURES depends on device segment multi input MCBs only Software selectable HV shutdown mode SET SHOW VERI_SHUT Software selectable shaping time constants SET_SHAP Explorable shaping time constants SHOW_CONFIG_SHAP Advanced shaping time SET_SHAP_RISE SET_SHAPE_FLAT etc Software selectable BLR ENA DIS SHO_BLR_AUTO SET SHO VERI_BLR SHOW_STATUS command supported returns M record Overflow preset ENA DIS SHO_OVER_PRES Software enabled MicroNOMAD style audio clicker
108. these error responses rarely occur on systems with reliable communication hardware running debugged software The commands are listed in alphabetical order each starting with a command prototype line Uppercase letters numeric digits blank space and special symbols such as the underscore _ and comma 13 in the prototype line are literal text to be sent to the MCB exactly as they appear Lowercase letters in the prototype line represent numeric values as described in the accompanying text they should not be sent literally to the MCB but should be replaced by an appropriate numeric value In this section the term lt CR gt represents the ASCII carriage return character decimal value 13 and the character represents the ASCII underscore character decimal value 95 CLEAR The channels of spectral data in the window of interest see SET_WINDOW command are set to zero The live time and true time counters are also set to zero This command is equivalent to the combination of CLEAR_COUNTERS and CLEAR_DATA commands 33 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 CLEAR ALL This command is equivalent to the combination of CLEAR COUNTERS CLEAR DATA CLEAR PRESETS and CLEAR ROI commands CLEAR COUNTER The live time and true time counters are set to zero CLEAR DATA The channels of spectral data in the window of interest see SET WINDOW command are set to zero The ROI flags are not changed n
109. timize feature should be used with the LFR filter off Subsequent measurements can then be _ Gee taken with the LFR filter on Figure 17 DSPEC jr 2 0 ADC Tab 30 931010D 0914 2 GETTING STARTED 2 3 4 ADC This tab Fig 18 contains the f Properties for DSJ2 908 Gate ZDT Mode Conversion c E E GAR ANE i age out atus resets reset Gain Lower Level Discriminator Ampifer Ampi er2 AmpiferPRO ADC Stablizer and Upper Level Discriminator con a Gate E ion Gain T3553 trols In addition the current real lor E li 3 time live time and count rate are SET Lower Level Disc 50 monitored at the bottom of the ff Upper Level Disc 16383 H dialog Gate This control allows you made EN to select a positive TTL logic level 0 00 0 00 Count Rate 0 gating function With gating Off no gating is performed that is all detec tor signals are processed with gating in Coincidence mode a gating input signal must be present at the proper time for the conversion of the event in Anticoincidence mode the gating input signal must not be present for the conversion of the detector signal The gating signal must occur prior to and extend 500 ns beyond peak detect peak maximum Figure 18 DSPEC jr 2 0 ADC Tab ZDT Mode See Section 1 4 for a detailed discussion of this feature Use this droplist to choose the Off LTC spectrum only or CORR ERR ERR and ZDT spe
110. ting point microseconds 4 FIRMWARE COMMANDS AND RESPONSES Most software communication with the DSPEC jr 2 0 takes place through the CONNECTIONS software layer CONNECTIONS is used by all ORTEC software and can be accessed for other software development with our CONNECTIONS Programmer s Toolkit with Microsoft ActiveX Controls A11 Use the DLL interface call MIOComm or the ActiveX control UCONN s Comm method to send commands to instruments and receive responses 4 1 Command Format The commands consist of a command header that may be followed by numeric parameter values The header consists of a verb a verb and noun or a verb noun and modifier each separated by underscores The first four letters of a word in a command will always be enough to uniquely identify that word when composing commands for the instrument For example the command ENABLE_GAIN_STABILIZATION can be abbreviated to ENAB_GAIN_STAB Numeric parameters are unsigned integer numbers that follow the command header separated by one or more spaces Specific commands require multiple parameters separated by commas that specify numeric quantities related to the operation of the MCB such as live time or conversion gain The command SET_WINDOW 0 8192 has two parameters O and 8192 which set the window of interest to start at channel O and continue for 8192 channels Some parameters are optional and are delimited by square brackets in the command prototype line to distingu
111. tion and throughput see Section 2 4 This setting affects both the rise and fall times so changing it spreads or narrows the quasi trapezoid symmetrically Qose InSight Start Stop f 220 Figure 14 DSPEC jr 2 0 Amplifier 2 Tab Use the up down arrows to set the Rise Time from 0 8 to 23 0 us Once the unit has been optimized according to Section 2 3 1 you can use any Rise Time without having to re optimize The value of the rise time parameter in the DSPEC jr 2 0 is roughly equivalent to twice the inte gration time set on a conventional analog spectroscopy amplifier Thus a DSPEC jr 2 0 value of 12 us corresponds to 6 us in a conventional amplifier Starting with the nominal value of 12 0 you should increase values of the rise time for better resolution for expected lower count rates or when unusually high count rates are anticipated reduce the rise time for higher throughput with somewhat worse resolution The Flattop controls adjust the top of the quasi trapezoid The Width adjusts the extent of the flattop from 0 3 to 2 4 us The Tilt adjustment varies the flatness of this section slightly The Tilt can be positive or negative Choosing a positive value results in a flattop that slopes down ward choosing a negative value gives an upward slope Alternatively the optimize feature on the Amplifier tab can set the tilt value automatically This automatic value is normally the best for resolution
112. ts designed to expose any flaws in materials or workmanship Permanent records of these tests are maintained for use in warranty repair and as a source of statistical information for design improvements Repair Service If it becomes necessary to return this instrument for repair it is essential that Customer Services be contacted in advance of its return so that a Return Authorization Number can be assigned to the unit Also AMT must be informed either in writing by telephone 865 482 4411 or by facsimile transmission 865 483 2133 of the nature of the fault of the instrument being returned and of the model serial and revision Rev on rear panel numbers Failure to do so may cause unnecessary delays in getting the unit repaired The AMT standard procedure requires that instruments returned for repair pass the same quality control tests that are used for new production instruments Instruments that are returned should be packed so that they will withstand normal transit handling and must be shipped PREPAID via Air Parcel Post or United Parcel Service to the designated AMT repair center The address label and the package should include the Return Authorization Number assigned Instruments being returned that are damaged in transit due to inadequate packing will be repaired at the sender s expense and it will be the sender s responsibility to make claim with the shipper Instruments not in warranty should follow the same procedure and AMT
113. ue time preset reported as 4294967295 ticks SHOW_TRUE_REMAINING Reports the current true time remaining in units of 20 milliseconds 50 ticks per second See also SET_TRUE_REMAINING Responses G0000000000075 lt CR gt True time remaining reported as disabled G0000000001076 lt CR gt True time remaining reported as 1 tick G4294967295132 lt CR gt True time remaining reported as 4294967295 ticks SHOW_ULD Returns the value of the ULD in channels as a C record SHOW_UNCERTAINTY Returns the current value of the uncertainty for the peak in the uncertainty preset See also SET_UNCERTAINTY Responses UNCE 0000000000008 5 Uncertainty of the peak is 8 5 84 931010D 0914 4 FIRMWARE COMMANDS AND RESPONSES SHOW_UNCERTAINTY_PRESET Returns the current uncertainty preset setting See also SET UNCERTAINTY PRESET Responses UNCE PRES 000000000000000 No preset UNCE PRES 0000000000008 5 Preset set to 8 596 SHOW VERSION Reports the DSPEC jr 2 0 firmware version number in the form Fmmmm vvv CR where mmmm is a 4 character model designator and vvv is a 3 character version designator Example Responses FDSJR 002 lt CR gt Model DSPEC jr 2 0 firmware Version 2 reported SHOW_WINDOW Reports the start channel and number of channels in the window of interest in the form Dxxxxxyyyyyccc lt CR gt where xxxxx is the start channel 0 16383 and yyyyy is the number of channels 1 16384 See SET_WINDOW for more information
114. ument entry in the Configure Instruments dialog This will open the Change Description or ID dialog Fig 12 It shows the physical MCB location read only and allows you to change the ID Number and Description f Change Description or ID Instrument Input System ID 132 1 USER PC 19 Nu Cancel Description Figure 12 Change MCB Number or Description Make the desired changes and click Close Any changes you have made to an ID number or description will then be written back to the corresponding MCB If this is a first time installation of ORTEC products all your instruments will be new 22 931010D 0914 2 GETTING STARTED NOTE FOR MULTIPLE USERS ON A NETWORK There are two ways to reduce the chance that other users will renumber your MCBs e Add the I flag to their MCB Configuration command line as described in the CONNECTIONS Driver Update Kit instructions This will allow you to assign whatever ID Numbers you wish regardless of the numbers assigned by other users on your network Ideally everyone using ORTEC instruments on your network should make this change To prevent others from renumbering your MCBs or performing any other actions except read only viewing password lock your MCBs with the MAESTRO Lock Unlock Detector command If you lock a detector that will be controlled by a JOB stream remember to include the proper password unlock commands in your JOB file see the MAESTRO u
115. us Use the SET_OUTPUT_HIGH or SET_OUTPUT_LOW commands to establish an initial output level Responses C00000087 lt CR gt Initial and final level on Change Sample was low C00001088 lt CR gt Initial and final level on Change Sample was high STOP seg mask Stops the acquisition of spectral data The optional segment mask is provided for compati bility with other MCBs and may be any value from 0 to 65535 but is ignored STOP_OPTIMIZE Stops the optimization in progress The DSPEC jr 2 0 may be in an indeterminate mode See also START_OPTIMIZE STOP_PZ_AUTOMATIC Stops the optimization in progress The DSPEC jr 2 0 may be in an indeterminate mode See also START PZ AUTOMATIC TRIGGER Starts data acquisition if the trigger has been enabled ENABLE TRIGGER VERIFY CORR FLAT VERIFY SHAP FLAT VERIFY SHAP RISE These test the argument against the list of valid settings and return true if valid 87 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 Intentionally blank 88 APPENDIX A STATE OF HEALTH BIT DEFINITIONS Following are descriptions of the SOH bit To monitor these within MAESTRO click Acquire MCB Properties then on the Status tab see Fig 26 Bit Bb N r Properties for DSJ2 908 Amplifier Amplifier2 AmplifierPRO ADC Stabilizer High Voltage About Status Presets MDAPreset PERERA ox Dim 24 State Of Heat OK GT DM 412 State OfHeath OK
116. when periodic noise is present Figure 2 Example of Weighting Function Output Resulting from the Positive Slope Due to Low Frequency Noise shown as a sine wave Figure 4 shows the calculated frequency response of the typical trapezoid filter dashed line and the LFR enabled filter solid line The graph shows the output of the systems for a typical 10 us rise time setting of both filters The x axis is the frequency of the noise in the system At 3 kHz the improvement in response to the noise is roughly an order of magnitude with the LFR enabled filter 931010D 0914 1 INTRODUCTION InSight BEDWELL MCB 163 8 x File Acquire Calculate Services ROI Display al Di A 207 f do uu 18520weL mci z Mark Peak w Trigger Random a Iv Single Reset Delay 0 00 E Baseline Restorer Auto fa uS Fast C C Slov up eo Fole Zero Auto 3237 3 Other Controls ORTEC 1247 32 PM Tue 4 1 2003 Marke 1 435 143 50 p5 1 039 Cnts Figure 3 LFR Enabled Digital Filter To switch to LFR mode click the Amplifier PRO tab under Acquire MCB Properties and mark the Low Frequency Rejector checkbox see Section 2 3 3 Note that you cannot opti mize or pole zero the DSPEC jr 2 0 while in LFR mode The Optimize feature should be used with the LFR filter off checkbox unmarked Subsequent measurements can then be taken with the LFR filter on DSPEC j
117. wn is active supply is shut down or can t be turned on IF Shutdown is inactive supply is on or can be turned on SHOW_SNUM Responds with a F record indicating the serial number of the DSPEC jr 2 0 Response F100 Serial number 100 81 DSPEC jr 2 0 Digital Gamma Ray Spectrometer User s Manual 951010D 0914 SHOW STATUS Returns system status information in the following format MIIIIIIlttttttttttaaaaahhhhhcccc CR where 1111111111 represents the live time as returned by the SHOW LIVE command tttttttttt represents the true time for the current device as returned by the SHOW TRUE command aaaaa represents the active device mask as returned by the SHOW ACTIVE DEVICES command and hhhhh represents the hardware status which is an ASCII representation of a 16 bit decimal number with the following bit definitions Bit 0 LSB Bias supply polarity O positive 1 negative Bit 1 Bias supply overload O overload 1 normal Bit 2 High voltage enabled O disabled 1 enabled Bit 3 Unused Bit 4 Amplifier PZ d since initialization O normal 1 needs PZ ing Bit 5 Optimization since initialization O normal 1 needed Bits 6 7 Unused Bit 8 Amplifier automatic PZ 1 Auto PZ in progress 0 normal Bit 9 Optimization O normal 1 in progress Bits 10 14 Unused Bit 15 MSB Reserved SHOW_THRESHOLD_AUTOMATIC See also SET_THRESHOLD_AUTOMATIC Responses IT lt CR gt Automatic threshold is enabled IF lt CR
118. y dim oi e dedos Vet ats 32 23 07 INV MALE A ee are dantis 33 DS AO WEE 34 O O Se A epee sonar mate S ale as 34 Dd HMC SL E atria A EN E r NO TR E E aE ETE ETRS 37 2 9 A MDA Preset UA Ad is 38 2 4 Setting the Rise Time in Digital MCBs 0 ccc cece eens 40 2 5 TTOUDICSHOOUING A E A a ae eh es 4 2 5 1 MAESTRO Does Not Connect with the DSPEC jr 2 0 41 3 SPECIFICATIONS oea a y SUR EEK A O A a id 43 E II A II A DRE EO Ree oe ee SR RS 43 3 1 1 Electrical and Mechanical std a cy saw ES 45 le COMMCCIONS diran pira 46 3 2 HPGe High Voltage Detector Interface Modules 0 0 00 c eee eee 46 3 9 Feature Mask Bits e ER ada dt PA 47 4 FIRMWARE COMMANDS AND RESPONSES sseeeee eee eens 51 Z1 AROMA ORIN s ho Sg cae sh a ahs Sica pm Ob ic aet ppt based ded aap PEH EE ae 51 d Error Codes rodas one AAA ong pav 51 4 2 1 Dollar Response Records a2 ack ee ne eae Heed be aha we e RAE DERE 32 4 2 2 MCB COMMANOS do Sod Sabe A QI PER ie 53 APPENDIX A STATE OF HEALTH BIT DEFINITIONS 0 000000 89 IND esed uu Pa I EM PI Ud b A E 9 Safety Instructions and Symbols This manual contains up to three levels of safety instructions that must be observed in order to avoid personal injury and or damage to equipment or other property These are DANGER Indicates a hazard that could result in death or serious bodily harm if the safety instruction is not observed WARNING Indic

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