Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301218
D. Binkley
Monte Carlo analysis is used to model statistical noise associated with scintillation-detector photoelectron emissions and photomultiplier tube operation. The impulse response of a photomultiplier tube, front-end amplifier, and constant-fraction discriminator (CFD) is modeled so that the effects of front-end bandwidth and constant-fraction delay and fraction can be evaluated for timing-system optimizations. Monte Carlo timing resolution for a bismuth germanate (BGO)/photomultiplier scintillation detector, CFD timing system is presented as a function of constant-fraction delay for 511-keV coincident gamma rays in the presence of Compton scatter. Monte Carlo results are in good agreement with measured results, indicating better timing resolution with decreasing constant-fraction delay. Monte Carlo energy-discrimination performance is experimentally verified along with the timing resolution (Monte Carlo resolution of 3.1 ns FWHM versus measured resolution of 3.3 ns FWHM) for a front-end rise time of 10 ns (10-90%). CFD delay of 8 ns, and CFD fraction of 20%.<>
{"title":"Optimization of scintillation-detector timing systems using Monte Carlo analysis","authors":"D. Binkley","doi":"10.1109/NSSMIC.1992.301218","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301218","url":null,"abstract":"Monte Carlo analysis is used to model statistical noise associated with scintillation-detector photoelectron emissions and photomultiplier tube operation. The impulse response of a photomultiplier tube, front-end amplifier, and constant-fraction discriminator (CFD) is modeled so that the effects of front-end bandwidth and constant-fraction delay and fraction can be evaluated for timing-system optimizations. Monte Carlo timing resolution for a bismuth germanate (BGO)/photomultiplier scintillation detector, CFD timing system is presented as a function of constant-fraction delay for 511-keV coincident gamma rays in the presence of Compton scatter. Monte Carlo results are in good agreement with measured results, indicating better timing resolution with decreasing constant-fraction delay. Monte Carlo energy-discrimination performance is experimentally verified along with the timing resolution (Monte Carlo resolution of 3.1 ns FWHM versus measured resolution of 3.3 ns FWHM) for a front-end rise time of 10 ns (10-90%). CFD delay of 8 ns, and CFD fraction of 20%.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134538559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Newcomer, R. Van Berg, H. Williams, S. Tedja, J. van der Spiegel
The ASD-8 is a bipolar integrated circuit that provides eight channels of amplifier, shaper, and discriminator on a 2.8*4.7 mm silicon substrate. It was designed for use in the straw-based central tracking system of the SDC detector. Competing requirements for short measurement time ( approximately= 15 mW/ch), and low operational threshold ( approximately=1 fC) led to the choice of a largely differential circuit which includes detector tail compensation. Threshold control with lockout is provided for each discriminator. Tests with parts from a recently fabricated prototype run indicate excellent yield and stable operation with little or no internal crosstalk.<>
{"title":"A fast, low power amplifier, shaper and discriminator for high rate straw tracking systems","authors":"F. Newcomer, R. Van Berg, H. Williams, S. Tedja, J. van der Spiegel","doi":"10.1109/23.256630","DOIUrl":"https://doi.org/10.1109/23.256630","url":null,"abstract":"The ASD-8 is a bipolar integrated circuit that provides eight channels of amplifier, shaper, and discriminator on a 2.8*4.7 mm silicon substrate. It was designed for use in the straw-based central tracking system of the SDC detector. Competing requirements for short measurement time ( approximately= 15 mW/ch), and low operational threshold ( approximately=1 fC) led to the choice of a largely differential circuit which includes detector tail compensation. Threshold control with lockout is provided for each discriminator. Tests with parts from a recently fabricated prototype run indicate excellent yield and stable operation with little or no internal crosstalk.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133069068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301152
G. Baldwin, C. O. Landron, L. Lorence
The Time Projection Compton Spectrometer (TPCS) has previously been used with a 12.7- mu m-thick polypropylene target to measure the time-integrated energy spectrum of intense flash X-ray sources. In the present work, the authors investigated the application of the TPCS to photoelectron spectrometry, substituting a 2- mu m thick gold target to improve device sensitivity to low-energy photons. Experiments with a gold target, a polypropylene target, and no target (background) were done at the Saturn pulsed X-ray source for various endpoint bremsstrahlung up to about 2 MV. Response functions were calculated using the TIGERP electron/photon Monte Carlo code. The signal from gold is larger and persists longer, as expected. The spectrum unfolded from the gold signals has problems, however. Alternative approaches to the unfold problem that combine data from both targets may prove more successful. If so, a future spectrometer could be designed to incorporate both low-Z and high-Z targets in a single instrument.<>
{"title":"Extending the range of the Time Projection Compton Spectrometer to lower energy","authors":"G. Baldwin, C. O. Landron, L. Lorence","doi":"10.1109/NSSMIC.1992.301152","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301152","url":null,"abstract":"The Time Projection Compton Spectrometer (TPCS) has previously been used with a 12.7- mu m-thick polypropylene target to measure the time-integrated energy spectrum of intense flash X-ray sources. In the present work, the authors investigated the application of the TPCS to photoelectron spectrometry, substituting a 2- mu m thick gold target to improve device sensitivity to low-energy photons. Experiments with a gold target, a polypropylene target, and no target (background) were done at the Saturn pulsed X-ray source for various endpoint bremsstrahlung up to about 2 MV. Response functions were calculated using the TIGERP electron/photon Monte Carlo code. The signal from gold is larger and persists longer, as expected. The spectrum unfolded from the gold signals has problems, however. Alternative approaches to the unfold problem that combine data from both targets may prove more successful. If so, a future spectrometer could be designed to incorporate both low-Z and high-Z targets in a single instrument.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125319217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301177
Q. Bristow
Summary form only. A technique for the post-acquisition correction of distortion in radiation spectra due to pulse pileup is considered. Data have been obtained showing the application of this method in removing pileup distortion from Ge spectra acquired at high count rates. The results obtained have been compared with spectra acquired using a hardware pulse pileup rejector under identical conditions. A method for determining the effective pulse rise-time of a given MCA system (as seen by the system ADC) has been considered and the relevant theory has been examined. It is based on the comparison of low and high count rate spectra acquired by the system at known input count rates.<>
{"title":"Application of a post-acquisition pileup correction algorithm to high count rate Ge spectra","authors":"Q. Bristow","doi":"10.1109/NSSMIC.1992.301177","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301177","url":null,"abstract":"Summary form only. A technique for the post-acquisition correction of distortion in radiation spectra due to pulse pileup is considered. Data have been obtained showing the application of this method in removing pileup distortion from Ge spectra acquired at high count rates. The results obtained have been compared with spectra acquired using a hardware pulse pileup rejector under identical conditions. A method for determining the effective pulse rise-time of a given MCA system (as seen by the system ADC) has been considered and the relevant theory has been examined. It is based on the comparison of low and high count rate spectra acquired by the system at known input count rates.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132011850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301393
R.E. Byskosh, A. Alsammarae
The authors present a completely solid-state protective device based on power MOSFETs for low-voltage AC power circuits. This device includes not only solid-state sensing and tripping circuits but also a solid-state means of interruption. The operation of the power switch in various operating conditions is analyzed to determine its control requirements and design limitations.<>
{"title":"Application of power MOSFETs in protective devices for AC power circuits","authors":"R.E. Byskosh, A. Alsammarae","doi":"10.1109/NSSMIC.1992.301393","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301393","url":null,"abstract":"The authors present a completely solid-state protective device based on power MOSFETs for low-voltage AC power circuits. This device includes not only solid-state sensing and tripping circuits but also a solid-state means of interruption. The operation of the power switch in various operating conditions is analyzed to determine its control requirements and design limitations.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"327 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134258433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301006
E. Di Sciasco, R. Guzzardi, D. Marino
A specialized real-time reconstruction processor for three-dimensional positron emission tomography is proposed. It is based on an expandible SIMD (single-instruction multiple-data) parallel line processor. It is completely parallel and pipelined, and it is based on a bit-serial approach. The architecture, extremely suitable for ASIC (application-specific integrated circuit) implementation, has been designed to be compatible with existing tomograph prototypes, but it is easily scalable towards foreseen new solutions. The reconstruction processing time of the single coincidence line is of the order of the address-encoding time (at present 256 ns). The silicon design, in the SOLO 2030+41 environment with ES2 standard cells, is in progress, and it has been validated by simulations performed using the SILOS II simulator.<>
{"title":"Proposal of a real time reconstruction processor for 3-D positron emission tomography","authors":"E. Di Sciasco, R. Guzzardi, D. Marino","doi":"10.1109/NSSMIC.1992.301006","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301006","url":null,"abstract":"A specialized real-time reconstruction processor for three-dimensional positron emission tomography is proposed. It is based on an expandible SIMD (single-instruction multiple-data) parallel line processor. It is completely parallel and pipelined, and it is based on a bit-serial approach. The architecture, extremely suitable for ASIC (application-specific integrated circuit) implementation, has been designed to be compatible with existing tomograph prototypes, but it is easily scalable towards foreseen new solutions. The reconstruction processing time of the single coincidence line is of the order of the address-encoding time (at present 256 ns). The silicon design, in the SOLO 2030+41 environment with ES2 standard cells, is in progress, and it has been validated by simulations performed using the SILOS II simulator.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131535875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301366
F. Frontera, D. Dal Fiume, G. Landini, E. Artina, M. Biserni, V. Chiaverini, F. Monzani, E. Costa, R. C. Butler
The high-energy (15-300 keV) experiment PDS is one of the four narrow-field instruments on board the Italian-Dutch SAX satellite. The PDS detector is composed of four actively shielded NaI(Tl)/CsI(Na) phoswich scintillators and has a field of view of 1.4 degrees (FWHM). The total geometric area is 795 cm/sup 2/. The authors present a description of the instrument and its development status with particular emphasis on the performance of the pulse shape analysis electronics.<>
{"title":"The high energy experiment PDS (=phoswich detection system) on board the X-ray astronomy satellite SAX","authors":"F. Frontera, D. Dal Fiume, G. Landini, E. Artina, M. Biserni, V. Chiaverini, F. Monzani, E. Costa, R. C. Butler","doi":"10.1109/NSSMIC.1992.301366","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301366","url":null,"abstract":"The high-energy (15-300 keV) experiment PDS is one of the four narrow-field instruments on board the Italian-Dutch SAX satellite. The PDS detector is composed of four actively shielded NaI(Tl)/CsI(Na) phoswich scintillators and has a field of view of 1.4 degrees (FWHM). The total geometric area is 795 cm/sup 2/. The authors present a description of the instrument and its development status with particular emphasis on the performance of the pulse shape analysis electronics.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"261 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129088534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301229
B. Vallage
Summary form only. SiCAL, the new ALEPH small-angle luminosity calorimeter, has been built at Saclay. The design and performance of this compact silicon-tungsten calorimeter which will provide a more powerful luminosity measurement, both statistically and systematically. Exposure of a prototype of this detector to a 50 GeV electron beam at CERN has been investigated and compared with EGS simulations. The improvement in systematic accuracy has been considered.<>
{"title":"Results from SiCAL, the new Aleph small-angle luminosity calorimeter","authors":"B. Vallage","doi":"10.1109/NSSMIC.1992.301229","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301229","url":null,"abstract":"Summary form only. SiCAL, the new ALEPH small-angle luminosity calorimeter, has been built at Saclay. The design and performance of this compact silicon-tungsten calorimeter which will provide a more powerful luminosity measurement, both statistically and systematically. Exposure of a prototype of this detector to a 50 GeV electron beam at CERN has been investigated and compared with EGS simulations. The improvement in systematic accuracy has been considered.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"41 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132154165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301267
H. Ikeda, Y. Fujita, M. Ikeda, S. Inaba, S. Okuno, M. Tanaka, T. Tsuboyama
Design studies on a front-end CMOS amplifier for a silicon strip detector of the KEK B-factory experiment are described in terms of circuit characterization, and prototype fabrication and evaluation. Extrapolating the prototype performance to the B-factory design, the authors estimated the equivalent noise charge of 1000 electrons at 20 pF with an nMOS input FET. A pipeline analog memory, a built-in gain stage, and a flip-chip assembly were key elements of the design.<>
{"title":"Design considerations of CMOS VLSI for KEK B-factory silicon microvertex detector","authors":"H. Ikeda, Y. Fujita, M. Ikeda, S. Inaba, S. Okuno, M. Tanaka, T. Tsuboyama","doi":"10.1109/NSSMIC.1992.301267","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301267","url":null,"abstract":"Design studies on a front-end CMOS amplifier for a silicon strip detector of the KEK B-factory experiment are described in terms of circuit characterization, and prototype fabrication and evaluation. Extrapolating the prototype performance to the B-factory design, the authors estimated the equivalent noise charge of 1000 electrons at 20 pF with an nMOS input FET. A pipeline analog memory, a built-in gain stage, and a flip-chip assembly were key elements of the design.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131924469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1992-10-25DOI: 10.1109/NSSMIC.1992.301173
W. Moses
Summary form only. A method for using a modern TDC (time-to-digital converter) to increase the scintillation lifetime measurement rate by a factor of over 300 is discussed. It uses the delayed coincidence method, where a start photomultiplier tube (PMT) provides a signal synchronized to the excitation of the specimen and a stop PMT samples the resulting fluorescent lifetime spectrum. Typical data acquisition rates are low because the light collection efficiency of the stop PMT is artificially limited to in approximately=0.001 fluorescent photons per start signal to reduce the probability of detecting >1 photon per excitation. Some modern TDCs can detect whether additional stop signals occur during the sampling period and thus reject events in which >1 stop photons are present. This allows in to be increased to 1, which maximizes the data acquisition rate at a value over 300 times higher. Multi-hit TDCs can digitize the arrival times of n stop signals per start signal, which allows in to be increased to approximately=n. Since multiple photon events, which usually bias the data, are eliminated or measured, this method also improves the measurement accuracy.<>
{"title":"A method to increase scintillation lifetime measurement rates using a multi-hit TDC","authors":"W. Moses","doi":"10.1109/NSSMIC.1992.301173","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301173","url":null,"abstract":"Summary form only. A method for using a modern TDC (time-to-digital converter) to increase the scintillation lifetime measurement rate by a factor of over 300 is discussed. It uses the delayed coincidence method, where a start photomultiplier tube (PMT) provides a signal synchronized to the excitation of the specimen and a stop PMT samples the resulting fluorescent lifetime spectrum. Typical data acquisition rates are low because the light collection efficiency of the stop PMT is artificially limited to in approximately=0.001 fluorescent photons per start signal to reduce the probability of detecting >1 photon per excitation. Some modern TDCs can detect whether additional stop signals occur during the sampling period and thus reject events in which >1 stop photons are present. This allows in to be increased to 1, which maximizes the data acquisition rate at a value over 300 times higher. Multi-hit TDCs can digitize the arrival times of n stop signals per start signal, which allows in to be increased to approximately=n. Since multiple photon events, which usually bias the data, are eliminated or measured, this method also improves the measurement accuracy.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133384487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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