Multiport Multichannel Analyzer User`s Manual
Contents
1. Dwell Time for MCS mode Note that this parameter is also adjustable within the Gamma Acquisition and Analysis application e Coincidence Mode and Dead Time Mode for the Models MPT 8E and MPT 16E with internal ADC e Multiple Memory Groups are selectable only from within the MID Editor The editing procedure is described in Editing an MCA Definition in the MCA Input Definition chapter of the Genie 2000 Operations Manual That chapter also has de tailed information on using the MID Editor The MCA Adjust Screens The MCA Adjust Screens which are accessed from the Gamma Acquisition and Analysis application s Menu Bar allow you to adjust the Multiport s programmable controls As adjustments are made in the dialog box the new values are sent to the Multiport To save the adjustments to the datasource s CAM file use the Gamma Acquisition and Analysis application s File Save command so that the next time this datasource is se lected the proper setting will be loaded into the Multiport The MCA Adjust Screens The Next and Prev ious buttons at the left side of the Adjust screen are used to move to the next or previous page of the controls when there are more control elements than will fit in the basic box To access the Adjust screens a Multiport datasource must have been opened To open select File Open Datasource then select Detector in the Type box Next select the datasource file and click2. IEEE 488 MADE IN USA 1 0 Connector for auxiliary I O signals ADC IN Accepts positive unipolar or bipolar positive lobe leading pulses for PHA or pulses for MCS mode EXT ADC Connects Multiport to an External ADC DMR Connects Multiport to a Digital Multiplexer Router not currently available or External ADC IEEE 488 Port for IEEE 488 communication with host computer BIN POWER Accepts power from the NIM Bin Figure 2 Rear Panel Connectors MPT EXE IEEE 488 Setup and Configuration 3 Setup and Configuration This chapter will guide you through to connecting and setting up the system Installation The Canberra Model 2100 Bin and Power Supply or other bin and power supply sys tems conforming to the mechanical and electrical standards set by DOE ER 00457T will accommodate the Multiport MCA The module s right side cover acts as a guide for insertion of the instrument The module is secured by turning the two front panel captive screws clockwise until finger tight It is recommended that the NIM bin power switch be OFF whenever the module is installed or removed To ensure safety be sure to use a NIM Bin which complies with all applicable safety requirements The Multiport can be operated where the ambient air temperature is between 0 C and 50 C 120 F maximum Perforations in the top and bottom sides
3. 20 ACEPT 21 ENDATA 22 CDT 23 ENC 24 READY 25 INB 26 ADCOO 27 ADCO1 28 ADCO2 29 ADCO3 30 ADC04 31 ADCO5 32 ADCO6 33 37 26 Rear Panel Connector Pinouts Description Ground Output Output Output Output Output Output Output binary data binary data 2 MSB 7 binary data 8 binary data 10 binary data 11 gt pA O m git Sia yf binary data 12 r2 2 2 binary data 2 jee 2 2 No connection Input Data Accepted Signals the ADC that the data has been accepted by the MCA ACEPT may reset when READY resets handshake Input Enable Data Used to enable the tri state buffers driving the 14 bits of data onto the output lines ADCOO through ADC13 Output Composite Dead Time This signal indicates the time when the ADC or connected amplifier is busy and cannot accept another input event It is used to gate the live time clock circuit in the MCA Input Enable Converter This signal enables or disables the ADC module Logic 1 enables ADC operation Logic 0 prevents the ADC from reopening the linear gate thereby inhibiting further operation Output Data Ready Indicates that data is available for transfer to the MCA READY will be reset after receipt of signal ACEPT Output Inhibit This signal indicates that the data available for transfer to the MCA is invalid and although the data transfer must be completed the data itself should be discar
4. 488 interface makes the Multiport compatible with a wide variety of computer platforms IEEE 488 interface boards are available in ISA EISA and PCI bus form factors so the Multiport user need not worry about compatibility as computer bus standards evolve Also up to 15 Multiport units can be controlled from a single IEEE interface so a Multiport system does not consume more than a single PC slot By keeping all sensitive components out of the computer itself Multiport provides better performance and lower noise than plug in card based MCAs but at comparable prices Multiport is suitable for use with a wide range of radiation detectors Selecting a proper preamplifier amplifier and high voltage power supply makes Multiport com patible with Nal TD HPGe SiLi CdTe Ion Implanted Plastic scintillation BGO and other detector technologies Modular NIM packaging makes it easy to reconfigure sys tems as needs change or as new technologies become available A two point digital stabilizer is included to ensure system stability under a range of count rates and temperature variations Gain and zero stabilization are independently controlled to lock on high and low energy peaks respectively in the spectrum Sepa rate ranges for HPGe and Nal detectors ensure that stabilizer will operate correctly with either detector type For added flexibility the Multiport supports both pulse height analysis PHA and multichannel scaling MCS modes of
5. ae a 5 Creating an MCA Input Definition 0 200000 000000000000 6 The MID Wizards c oee teree a os Bee a oe eee Ew REE ER ew EER ERE De oS 6 The MCA Input Definition EditOr ee 8 The MCA Adjust Screens s so s aao maa atua ee ee 8 Stabilizer Parametrs sssi wowed ae Oe we hed we a eh ke wh ed 9 MCS Rarameters 2 poa ed ee ee ge Be et a D 11 ADC eree SR ww REE RE rea Se ERE EEE ow OE OEE EH ES 11 ACQUITE Set p Seres s edu goed e a a A a lea da Ade ae oes oe 12 4 Operation 13 Basic Spectroscopy Operations oses eosa ea e doao we hoe E D EE A E E E a E E E a 13 Gal eaka REGS goe da Se Be POE SHEE Cw Ee REE MER aa 13 Extermal Internal Syne 100 G4 aoa Ae a Ge dw A a as 13 MCES Mod s se adsl hee whe a ak ee Bae Melek e Gre 14 Digital Spectrum Stabilizer Operation 2 2 a 14 MAPUS a8 be o tee GE Ge ie A og Nd eer el Se we ee a 15 OUIUDUIS ois e a SA dee aes BS a A a A ees Bs AA 15 Controls iaee aiea a dee ea he He a a a Bae et Be Sable wy Ge a ar wo eH BG 16 Tadic ALOES a ch o ee ace fe aes Sere pe che we eet oe es eth ed ce a Pee ae 16 PTOCESSO 3 4 bao eG ee hee OS eK eee eee She ee eRe ee eee ed eK eS 16 Data Acquisition s a oos 2 084 Bee ese Ba a A Oe ee ee ae TE a 16 ADC ae ogee a ds Ae Ses ae a ee ee ee Se 16 MCS 2 be bdee ad eb bbe ra dd ae be bebe eG eb bo eee bes 17 Eiye Times Clock ie a hes BOE nese fe te as Ser aa dg ee Ge S 17 PEEN 2 4 4 gS ea G FY Oe ae Pale AAA SOLE OS ORES ee A 18 DCA ese
6. et Gee ig Seine UR Gate tes Aah Bot eo Bee a neyo a en GMA 18 Digital Stabilizers soi sans a E A ee Be ww 18 External ADC ocres 34a 404 be Howe Eee a DOD EES 18 System Requirements 18 Power Requirements 24 4 soari 5 rra 19 Physicals s as bee 4 ehh SOE be oea aam bE EY ERE ORES ECE e a OS ew EY 19 Environmental ovio msj ee i ee ae ee Re aed e we aan 19 Ordering Information eras ea e ee wR AA Sh 19 Installation and Controls lt lt lt 20 Installling the GPIB IEEE 488 Card 2 o e 20 Setting the Multiport s GPIB Address e 21 Setting the Internal Controls lt s sc essi rrean aptesa etma EEE EEE 22 Main Board Controls sessi aiaa a a aei ee 22 ADC Board Controls ca ecesas 048 bee Geo iea bE REAR SE REDS aa OSS 23 Rear Panel Connector Pinouts lt 25 MO Comectot 5 4 0 2 beet ewe whee eee ewe LAE ey eS CHE OED EDS 25 DMR Connector e tumor ae ee ew ey Be be ee hh Bad ow ae 26 TEEE 488 Connector 2 0 ee ee 27 1 Introduction The Multiport MCA meets the need for a cost effective mid performance general pur pose Multichannel Analyzer Packaged in a convenient double wide NIM module the Multiport is available in three versions 8K and 16K units with internal ADC and a 16K version for use with an external Canberra ADC Host computer interfacing is accomplished via an industry standard IEEE 488 parallel interface The widely accepted IEEE
7. may void your warranty Warranty Canberra s product warranty covers hardware and software shipped to customers within the United States For hardware and software shipped outside the United States a similar warranty is provided by Canberra s local representative
8. the selection button and adjust screen are hidden from view Y Adjust C ADC C Stab MCS Figure 8 Adjust Screen s MCS Settings Dwell Time Sets the dwell time value ADC The ADC setting screen Figure 9 for the Multiport contains the following controls This feature is available only for Multiport Models MPT 8E and MPT 16E Y Adjust x ADC C Stab er Offset _ Caine mode LTC PUR sig TCR Off AntiCo C Coincidence Figure 9 Adjust Screen s ADC Settings Setup and Configuration Offset Sets the ADC s digital offset in channels Coincidence Mode Sets the coincidence mode for the extended Gate signal when external gating is used Acquire Setup Screen The Gamma Acquisition and Analysis application s Acquire Setup Screen is described in detail in the Genie 2000 Operations Manual However the External Start option on this screen is of particular significance at this time Checking External Start enables Multiport s External Sync function which works in conjunction with the EXTSY signal at the rear panel I O port In PHA mode a positive TTL level enables data acquisition and the Real Time and Live Time clocks In MCS mode a positive TTL pulse starts restarts a sweep Basic Spectroscopy Operations 4 Operation The Multiport is supplied from the factory ready for normal pulse height analysis PHA operation The only external connections required are an IEEE 488 interf
9. 0 mA 12 V de 140 mA Power consumption 120 V ac 70 mA Physical SIZE Standard double width NIM module 6 86 x 22 12 cm 2 70 x 8 71 in per DOE ER 0457T NET WEIGHT 1 7 kg 3 8 Ib SHIPPING WEIGHT 2 1 kg 4 6 Ib Environmental OPERATING TEMPERATURE 0 to 50 C OPERATING HUMIDITY 0 80 relative non condensing Ordering Information MPT EXE 16K Multiport for use with external Canberra ADC MPT 8E 8K Multiport with internal 8 us ADC MPT 16E 16K Multiport with internal 8 us ADC Requires Genie 2000 software sold separately Installling the GPIB IEEE 488 Card B Installling the GPIB IEEE 488 Card The GPIB General Purpose Interface Bus communication card and software may be installed in the host computer by using the procedures in the applicable National In struments manual National Instruments Model AT GPIB TNT and PCI GPIB cards are recommended and are available from National Instruments or through Canberra Installation and Controls Follow installation and configuration instructions in the corresponding GPIB Card in stallation manual In most cases the default configuration settings are sufficient How ever the following settings will work Note that not all GPIB card models will display each of these settings during configuration Switch Setting Primary GPIB Address 0 Secondary GPIB Address None Base I O Address Interrupt Request DMA channel None
10. ADC Input Return Differential J301 1 to 2 ALWAYS factory use only Factory setting J101 23 I O Connector C Rear Panel Connector Pinouts I O Connector Pin Signal Description 1 SCA Single channel analyzer output positive TTL pulse Internal ADC only Normal dead time control mode OR of Input 2 ADC BSY Discriminator ADC Busy and Extended Busy Correction External dead time control mode uses BSYIN only for dead time control positive TTL pulse CHSMPL Sample changer output positive TTL pulse PKD ADC peak detect to reset indicator positive TTL pulse 5 MSB Indicates the Most Significant Bit of MCS address positive TTL pulse 6 ROI Event storage indicator adjustable width positive pulse 7 DACA 0 10 V analog output 8 DACB 0 10 V analog output 9 BSYIN Provides additional deadtime from amplifier positive TTL pulse 10 GATE Coincidence or Anti coincidence TTL pulse must occur 2100 ns before peak and remain gt 30 ns after peak 11 REJ Pile up reject signal positive TTL pulse 12 MCS MCS input positive TTL pulse duration lt 30 ns rate lt 10 MHz 13 EXTDW External dwell advance positive TTL pulse interval gt 10 us duration 230 ns latency lt 2 us dead time between channels lt 2 us 14 EXTSY Enable acquisition signal positive TTL pulse internally pulled high 15 GROUND Ground 25 DMR Connector Pin Signal 1 6 Gnd 7 ADC13 8 ADCO7 9 ADCO8 10 ADCO9 11 ADC10 12 ADC11 13 ADC12 14 19
11. Bus Timing 500 ns Cable Length for High Speed Disabled System Controller Yes 1 0 Timeout 10 sec Parallel Poll Duration Default Enable Auto Serial Polling Yes Enable CIC Protocol No Assert REN when SC No Terminate Read on EOS No Set EOI with EOS on Write No 8 bit EOS Compare No Send EOI at end of Write Yes EOS byte 0 The Base I O Address and Interrupt Request IRQ are not specified because they may have to be set individually for existing hardware and software 20 21 Installation and Controls Setting the Multiport s GPIB Address The Multiport s GPIB address is set by internal switch SW101 a six position dip switch located at the bottom of the module near the front panel refer to Figure 10 Main Board Controls on page 22 Switches 1 5 determine the GPIB address setting Each device on a bus must have a unique GPIB address Therefore if there are multi ple Multiports on the same bus or another device with GPIB address 1 then the Multiport s address may need to be changed Use the following switch table as a guide Note that address 0 is reserved for the IEEE 488 communication card in the computer As many as 16 Multiports may be operated from a single GPIB card Note that the Base I O Address and Interrupt Level IRQL may depend on existing hardware so you must determine the available Address and IRQL for your system GPIB A
12. Multiport Multichannel Analyzer User s Manual 9231564B 7 00 ISO 9001 SYSTEM C E CERTIFIED Copyright 2000 Packard BioScience Company All rights reserved The material in this manual including all information pictures graphics and text is the property of Packard BioScience Company and is protected by U S copyright laws and international copyright conventions No material in this manual may be reproduced published translated distributed or displayed by any means without written permission from Canberra Industries a division of Packard BioScience Company Canberra Industries 800 Research Parkway Meriden CT 06450 Tel 203 238 2351 FAX 203 235 1347 http www canberra com The information in this manual describes the product as accurately as possible but is subject to change without notice Printed in the United States of America Table of Contents 1 Introduction lt lt ee are eee we wee a a A Model MPT EXE Multiport External ADC Version 2 2 o e e 1 Models MPT 8E and MPT 16E Multiport Internal ADC Versions 2 Software Support ese ea ee eee OL RR REE AA 2 2 Controls and ComectorS 39 Front Pan l c oa a oe we Body a td ae ale wine y ed 3 Rear Panele anadir ee ee ee eee ee Lee eee whee eee 4 3 Setup and Configuration Installation s sae e a e a e a o a a EEE es 5 Connecting the System se ss w awoke ae ee a ee
13. ONNECTORS Front and rear panel INPUT RATE lt 10 MHz DWELL TIME Internal from 10 us to 60 s external 10 us minimum SYNC Internal or External DEAD TIME 2 Us between passes 2 us between channels PRESET 1 to 9 999 999 passes LOGIC INPUTS MCS positive TTL EXTDW positive TTL EXTSY positive TTL rear panel DB 15 connector LOGIC OUTPUT MSB positive TTL rear panel DB 15 connector Live Time Clock RESOLUTION 400 ns ACCUMULATION INTERVAL 10 ms TYPE Live time with reject extension Specifications Presets REAL TIME 1 to 9 999 999 seconds LIVE TIME 1 to 9 999 999 seconds ROI INTEGRAL 1 to 9 999 999 counts SCA ZERO 25 of full scale 15 turn front panel potentiometer LLD lt 1 to 105 of full scale 15 turn front panel potentiometer ULD 0 to 105 of full scale 15 turn front panel potentiometer Digital Stabilizer Internal zero and gain stabilization GAIN HPGe Range 3 1 nominal resolution 0 0125 channel nominal at 8192 channels Nal Range 12 5 nominal resolution 0 25 channel nominal ZERO Range 1 5 nominal resolution 0 03 channel nominal External ADC INTERFACE TTL interface cable rear panel DB 37 connector System Requirements COMPUTER Industry standard PC DISPLAY 640 x 480 VGA or 600 x 800 SVGA or higher Power Requirements Power Requirements 24 Vde 30mA 12 V dc 26 mA 24 V dc 3
14. ace cable to the computer and the ADC input signal from a shaping amplifier Basic Spectroscopy Operations Refer to the Genie 2000 Operations manual for detailed instructions on basic spectros copy operations The following sections describe the Multiport s auxiliary functions which may be required in some applications They work in conjunction with input and output signals accessed through the supplied 14 lead cable connected to the Multiport s rear panel I O connector Gate The GATE signal is used in PHA mode to allow external control of events to allow particular events to be digitized and stored The Coincidence Mode option on the MCA Adjust screen ADC section contains two choices Off Anticoincidence and Coincidence Note that this feature is only applicable for use with the Internal ADC When external gating is not used Off Anticoincidence should be selected When no signal is attached the Gate input is pulled low internally so in this case Anticoinci dence essentially has the same effect as Off With an external signal attached the selection of Anticoincidence or Coincidence de termines how events will be digitized and stored When Coincidence is selected a TTL high signal on the GATE input at time of Peak Detect allows that particular event to be digitized and stored A TTL low signal at Peak Detect prevents digitization and storage of the event When Anticoincidence is selected a TTL low signal on the GATE input at tim
15. cations on page 15 Creating an MCA Input Definition After you ve installed the Genie 2000 software the first step in using your Multiport is to create an MCA Input Definition MID MID Wizard or MID Editor For most cases you ll use the MID Wizard to help you set up your Multiport s Input Definition quickly and easily If your Input Definition is more complex than the MID Wizard was designed to han dle you ll use the MID Editor page 8 to create or change your definition The MID Wizard To use the MID Wizard open the Genie 2000 folder and select the MID Wizard icon to start the definition process Step 1 The first screen Figure 3 lets you select the MCA you want to create a definition for Select the corresponding Multiport model from the list of MCAs MID Setup Wizard Step 1 To start select an MCA device from the list below Available MCAs cora tuo Figure 3 Selecting the MCA Setup and Configuration Step 2 The setup screen will ask you to define the GPIB Address and Board Number as shown in Figure 4 By default the Multiport has a GPIB address of 1 See Setting the GPIB Address on page 21 for instructions on changing the address The GPIB Board Number must equal the board number defined for the GPIB board in the GPIB Configuration MID Setup Wizard Step 2 Figure 4 Defining the GPIB Adress ans Board Number Step 3 The Step 3 screen in Figure 5 asks fo
16. ddress vs Switch Settings Ar SW SW2 s SW3 SW SWS 1 1 0 0 0 o 2 0 1 0 0 0 3 1 1 0 0 0 4 0 0 1 0 0 5 1 0 1 0 0 6 0 1 1 0 0 7 1 1 1 0 0 8 0 0 0 1 0 9 1 0 0 1 0 10 0 1 0 1 0 11 1 1 0 1 0 12 0 0 1 1 0 13 1 0 1 1 0 14 0 1 1 1 0 15 1 1 1 1 0 16 0 0 0 0 1 Factory Setting 0 closed switch 1 open switch Installation and Controls Setting the Internal Controls The Multiport s internal controls are shown in their factory default positions for both the Main Board and the ADC board Main Board Controls ZL 2 SCA output from SCA of internal ADC factory address 2 to 3 SCA output from Valid Event Conversion Power Source Figure 10 Main Board Controls Jigi 1 to 2 DAC A Output Negative 2 to 3 DAC A Output Positive J402 1 to 2 DAC B Output Negative 2 to 3 DAC B Output Positive J501 1 to 2 SCA Output from SCA of the internal ADC SCA Output from Valid Event Conversion Factory setting 22 Setting the Internal Controls ADC Board Controls 1 to 2 ADC input return grounded jadi factory default J101 2 to 3 ADC input return differential w ho 1 to 2 always factory use only ADC input signal from ADC in rear panel connector Factory use only J402 000 J01000 OOOCNA41 Figure 11 ADC Board Controls 1 to 2 ADC Input Return Grounded 2 to 3
17. ded by the MCA Output binary data 2 LSB Output binary data 2 2 Output binary data 3 Output binary data 5 Output binary data Output binary data 6 yi 2 2 ne 2 2 Output binary data No connection IEEE 488 Connector IEEE 488 Connector Pin 4 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 24 Signal B1 B2 B3 B4 EOI DAV NRFD NDAC IFC SRQ ATN SHD B5 B6 B7 B8 REN GROUND Description Data input output 1 Data input output 2 Data input output 3 Data input output 4 End or identify Data valid Not ready for data Not data accepted Interface clear Service request Attention Shield Data input output 5 Data input output 6 Data input output 7 Data input output 8 Remote enable Logic Ground 27 Request for Schematics Schematics for this unit are available directly from Canberra Write call or FAX Training and Technical Services Department Canberra Industries 800 Research Parkway Meriden CT 06450 Telephone 800 255 6370 or 203 639 2467 FAX 203 235 1347 If you would like a set of schematics for this unit please provide us with the following information Your Name Your Address Unit s model number Unit s serial number Note Schematics are provided for information only if you service or repair or try to service or repair this unit without Canberra s written permission you
18. e control mode uses BSYIN only for dead time control positive TTL pulse PKD ADC peak detect to reset indicator positive TTL pulse MSB Indicates the Most Significant Bit of MCS address positive TTL pulse ROI Event storage indicator adjustable width positive pulse SCA Single channel analyzer output positive TTL pulse CH SMPLE Sample changer output positive TTL pulse DACA 0 10 V analog output Specifications DACB 0 10 V analog output Controls RESET Front panel pushbutton Indicators DT METER Ten segment front panel multicolor LED bar graph ACQUIRE LED Front panel LED COMM BUSY Front panel LED Processor Intel 80C188 10 MHz clock ROM 128K x 8 RAM 64K x 8 data RAM 32K x 8 processor RAM Data Acquisition CHANNELS 16 384 configurable into input sizes of 8192 4096 2048 1024 512 or 256 channels ADC CONVERSION RATE Fully buffered 16 382 channel successive approximation 8 us ADC CONVERSION GAIN 16K 8K 4K 2K 1K 512 256 computer selectable RANGE From 0 to 10 V unipolar or bipolar positive lobe leading MCS MCS RISE TIME 0 5 us to 30 us INTEGRAL NONLINEARITY lt 0 05 over top 99 of range DIFFERENTIAL NONLINEARITY lt 1 over top 99 of range TEMPERATURE INSTABILITY Gain lt 100 ppm C zero drift lt 50 ppm C of full scale DIGITAL OFFSET Selectable in 256 channel blocks from 256 to 7936 INPUT C
19. e of Peak Detect allows the event to be digitized and stored A TTL high signal at Peak Detect prevents digitization and storage of the event External Internal Sync The EXTSY signal is used to control acquisition and specific behavior depends on ac quisition mode This function is enabled by checking External Start in the MCA Ac quire Setup screen Operation PHA Mode In PHA mode Data Acquisition must be started first by clicking the Acquire Start button Then a positive TTL Level applied to the EXTSY connector enables data ac quisition and RealTime and LiveTime clocks Note that the EXTSY Input is pulled high internally when no signal is attached which has the same effect enable as a high TTL input signal MCS Mode In MCS mode Data Acquisition must be started first as well Then a positive TTL pulse applied to the EXTSY connector starts the next sweep When no signal is at tached MCS sweeps will stop since the sweeps are triggered on pulse edges MCS Mode Input events are collected through the MCS connector in the form of positive TTL pulses To demonstrate the MCS operation connect the SCA connector to the MCS connector with a short length of BNC coaxial cable This connects the SCA output sig nal from the internal ADC to the MCS input You can set the desired MCS Dwell Time in the MCA Adjust screen page 8 Digital Spectrum Stabilizer Operation The Digital Spectrum Stabilizer is adjusted in the MCA Adjust screen
20. on open Note If you get a Required Hardware Unavailable error possible causes are selecting the wrong datasource for the instrument a problem with the IEEE 488 communication interface check the cable or the NIM Bin power is off If you get a Hardware Verification Error there is a mismatch be tween the MID Definition setup and the hardware configuration You can choose to accept or not accept the verification error in the associ ated dialog box If you select NO a RED error box will appear in the top left corner of the Gamma Acquisition and Analysis window To determine the source of the verification error open the Status Page by clicking MCA Status in the Acquisition and Analysis window The problematic item will be marked with an asterisk Each of the following sections describes one of the Multiport parameters that can be changed in the Gamma Acquisition and Analysis GAA application s Adjust dialog To change a parameter click on MCA Adjust in the GAA application s Main Menu then select the radio button for the parameter you want to change Stabilizer Parameters The Stabilizer settings screen Figure 6 for the Multiport contains the following con trols Y Adjust Lx Cabo Stab i Prev C On LJ gt 0 8192 0 Gain mode Gain centroid Gain spacing Zero mode a a gt Ochs ol Figure 6 Adjust Screen s Stabilizer Settings The MCA Adjust Screens Figure 7 show
21. operation In MCS mode a single channel ana lyzer SCA output is enabled as well as a SYNC input that allows acquisition to be synchronized by external apparatus Input rates of up to 10 MHz are supported Model MPT EXE Multiport External ADC Version For applications requiring no compromises performance in terms of count rate reso lution and temperature stability the Multiport can be paired with a Model 2060 Digital Signal Processor DSP For applications where requirements are not as stringent but where high performance ADCs are still desirable choose the Model 8701 Wilkinson ADC or the high speed Models 8713 or 8715 fixed dead time ADCs Introduction Models MPT 8E and MPT 16E Multiport Internal ADC Versions Where the convenience of an internal ADC is preferred the Multiport can be obtained in versions with integral 8K or 16K ADC The internal ADC is a fully buffered unit with a fixed dead time of 8 us Conversion gain can be set to 16K MPT 16E only 8K 4K 2K 1K 512 or 256 channels Analog input connections may be made through either front or rear panel BNC connections Software Support The Multiport is fully supported by Canberra s trend setting Genie 2000 software product family Genie 2000 supports a wide range of time proven spectral analysis al gorithms modern spectrum display and user interface as well as a variety of special applications programs Genie 2000 software solutions are available for application
22. page 8 It cor rects for drift in either high resolution Germanium Detectors or a low resolution Nal Detectors This feature is available only for Multiport Models MPT 8E and MPT 16E You can choose to correct zero shift gain shift or both Using a two point stabiliza tion method a high energy peak is monitored for gain drift and a low energy peak is monitored for zero drift The effective gain and zero intercepts of the ADC are ad justed to compensate for drift Specifications A Specifications Inputs LOGIC SIGNALS Rear panel DB 15 connector GATE Coincidence or Anti coincidence TTL pulse must occur 2100 ns before peak and remain 230 ns after peak REJ Pile up reject signal positive TTL pulse BSYIN Provides additional deadtime from amplifier positive TTL pulse EXTSY Enable acquisition signal positive TTL pulse internally pulled high MCS MCS input positive TTL pulse duration lt 30 ns rate lt 10 MHz EXTDW External dwell advance positive TTL pulse interval 210 us duration 230 ns latency lt 2 us dead time between channels lt 2 us ADC IN Front and rear panel BNC connector EXT ADC Rear panel DB 37 connector used with MPT EXE only COMMUNICATIONS Rear panel IEEE 488 parallel connector Outputs LOGIC SIGNALS Rear panel DB 15 connector ADC BUSY Internal ADC only Normal dead time control mode OR of Input Discriminator ADC Busy and Extended Busy Correction External dead tim
23. permit cooling air to circulate through the module When relay rack mounted along with other heat gen erating equipment adequate clearance should be provided to allow for sufficient air flow through both the perforated top and bottom covers of the NIM Bin Connecting the System Using the supplied cable connect the GPIB interface cable to the Multiport s IEEE 488 interface port and the other end of the cable to the interface port of the Host Computer s GPIB card This provides the communication between Multiport and the host computer For field installation instructions for the Multiport board refer to Appendix B Installing the IEEE 488 Board on page 20 Model MPT EXE Connect the supplied ribbon cable between the external ADC s DATA connector to the MPT EXE s EXT ADC connnector PB 37 Models MPT 8E and MPT 16E Connect a standard BNC cable between the Multiport s ADC IN connector and the amplifier s Output signal connector This provides the signal from the amplifier to the Multiport s internal ADC Note that this connector is not used with the Model MPT EXE Multiport which uses an external ADC DMR Currently the Multiport does not support a Digital Multiplexer Router DMR Creating an MCA Input Definition I O Optional external signals on this port are connected through the supplied 14 lead cable Each lead is labeled Descriptions of these signals can be found under Inputs and Outputs in Appendix A Specifi
24. r a Detector Type and acquisition memory size in channels and requires that an Input Name be entered For Multiport models with an internal ADC the maximum selectable memory size is limited by the ADC s maxi mum conversion gain MID Setup Wizard Step 6 6 El Figure 5 Assigning the Detector Type The MCA Input Definition Editor Ending the Definition To complete your Input Definition select Finish The input that you just defined will be stored as an MID file named inputname MID and automatically loaded into the Genie 2000 s MCA Runtime Configuration Database described in Using MCA Defi nition Tables in Chapter 3 MCA Input Definition of the Genie 2000 Operations Manual When you select Finish you will be asked if you would like to define an other input Answering No will close the Wizard Note that if you didn t enter an Input Name you won t be allowed to exit the Step 3 screen If the name you entered is the same as the name of an existing MID file the system will tell you so and go back to Step 3 to let you enter another name The MCA Input Definition Editor Most users will not need to use the MCA Input Definition MID Editor The MID Ed itor allows you to create edit and manage input definitions However for most users the facilities provided in the MID Wizard are sufficient You ll have to use the MID Editor only if you want to change any of the parameters listed below from their default values
25. s ranging as widely as laboratory gamma and alpha spectroscopy waste measurement whole body counting and nuclear safeguards Front Panel 2 Controls and Connectors Front Panel This is a brief description of the Multiport s front panel controls and connectors For more detailed information refer to Appendix A Specifications MPT 8E amp MPT 16E PCA Multiport Multichannel Analyzer DEADTIME 10 20 30 40 50 60 70 80 90 100 DEAD TIME Displays the converter s average dead time in incrementsof 10 ACQUIRE RESET COMBUSY 0 LLD Sets the Lower Leve Discriminator for the minimum input acceptance voltage ZERO Sets the input analog zero level ULD Sets the Upper Level Discriminator for the maximum input acceptance voltage ADC IN Accepts positive unipolar or bipolar positive lobe leading pulses for PHA or pulses for MCS mode MPT EXE PCA Multiport Multichannel Analyzer ACQUIRE RESET COMBUSY e a o ACQUIRE Indicates data acquisition in progress RESET Resets Multiport in event of communication failure Spectral data is left intact COM BUSY Indicates communication between Multiport and host computer Figure 1 Front Panel Controls and Connectors Rear Panel Controls and Connectors This is a brief description of the Multiport s rear panel connectors For more detailed information refer to Appendix A Specifications MPT 8E amp MPT 16E
26. s the relationship between the Stabilizer s Centroid and Spacing on a typical peak for both Zero Stabilization and Gain Stabilization See Stabilizer in Chapter 4 Gamma Acquisition and Analysis of the Genie 2000 Operations Manual for a fuller explanation of how a Stabilizer is used Spacing Centroid Figure 7 Relationship Between Stabilizer Functions Gain Centroid Sets the centroid in channels of the reference peak at the high end of the spectrum for gain stabilization Zero Centroid Sets the centroid in channels of the reference peak at the low end of the spectrum for zero Stabilization Gain or Zero Spacing Sets the spacing in channels between the upper and lower sampling channels The sampling channels should be placed so that a shift in the reference peak reflects a sig nificant change in count rate in the sampling channels For broad peaks the spacing should be set so that the sampling channels are not on the flat part of the peak Gain Mode Sets the Gain Stabilization mode to Off which disables the Stabilizer or On which enables the Stabilizer The MCA Adjust Screens MCS Parameters The MCS settings screen Figure 8 for the Multiport contains the following controls Note The MCS Adjust Screen and the associated selection button are available only if MCS was selected as the Acquisition Mode when setting up the MCA controls in the Devices MCA screen of the MID Editor If MCS was not selected
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