Pub Date : 1993-08-01DOI: 10.1109/NSSMIC.1992.301326
A. Lusiani
The performance and implementation of the TPC (time projection chamber) DAQ (data acquisition chamber) system are presented. It is shown how online data processing is used to obtain a substantial reduction of the data volume. The TPC DAQ system has performed in a satisfactory way since the beginning of LEP physics in 1989. The task of reliably initializing steering, and testing several hundred complex electronic modules has been achieved. Experience has shown that the complete system can operate reliably, provided it is properly monitored. The design requirements on TPPs (triple-width FASTBUS modules) and TPDs (double-width FASTBUS modules) were fulfilled, and their measured performance seems appropriate for the highest physics event rates expected at LEP. A substantial online reduction of the data volume has been obtained by making use of the processing power of 36 TPPs in parallel.<>
{"title":"Results in online data processing in the data acquisition system of the ALEPH TPC","authors":"A. Lusiani","doi":"10.1109/NSSMIC.1992.301326","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301326","url":null,"abstract":"The performance and implementation of the TPC (time projection chamber) DAQ (data acquisition chamber) system are presented. It is shown how online data processing is used to obtain a substantial reduction of the data volume. The TPC DAQ system has performed in a satisfactory way since the beginning of LEP physics in 1989. The task of reliably initializing steering, and testing several hundred complex electronic modules has been achieved. Experience has shown that the complete system can operate reliably, provided it is properly monitored. The design requirements on TPPs (triple-width FASTBUS modules) and TPDs (double-width FASTBUS modules) were fulfilled, and their measured performance seems appropriate for the highest physics event rates expected at LEP. A substantial online reduction of the data volume has been obtained by making use of the processing power of 36 TPPs in parallel.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128465360","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.1992.301266
E. J. Gerds, J. van der Spiegel, H. Williams, R. Van Berg
A time-to-charge converter with an analog memory unit (TCC/AMU) has been designed and fabricated in HP's 1.2 mu m n-well process. This VLSI chip is intended for the Superconducting Super Collider straw tube detector electronics. The TCC/AMU measures the time interval between the system clock and an asynchronous input, and then gives a digital output representing the time measurement. This initial version of the chip has analog Level 1 and Level 2 storage locations for data sparsification. Two separate fabrication runs resulted in chips that can measure intervals from 8 to 24 ns with approximately 108 ps/LSB resolution. When digital logic is added to count the reference clock, time resolutions of approximately 108 ps could be obtained over time intervals of approximately 1 s.<>
采用惠普公司的1.2 μ m n-well工艺，设计并制造了一款带有模拟存储单元(TCC/AMU)的充电时间转换器。这个超大规模集成电路芯片用于超导超级对撞机吸管管探测器电子器件。TCC/AMU测量系统时钟和异步输入之间的时间间隔，然后给出表示时间测量的数字输出。该芯片的初始版本具有用于数据稀疏化的模拟1级和2级存储位置。两次单独的制造运行导致芯片可以测量8到24 ns的间隔，分辨率约为108 ps/LSB。当添加数字逻辑来计数参考时钟时，可以在大约1.5秒的时间间隔内获得大约108ps的时间分辨率
{"title":"A CMOS time measurement system with analog memory for particle physics detectors","authors":"E. J. Gerds, J. van der Spiegel, H. Williams, R. Van Berg","doi":"10.1109/NSSMIC.1992.301266","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301266","url":null,"abstract":"A time-to-charge converter with an analog memory unit (TCC/AMU) has been designed and fabricated in HP's 1.2 mu m n-well process. This VLSI chip is intended for the Superconducting Super Collider straw tube detector electronics. The TCC/AMU measures the time interval between the system clock and an asynchronous input, and then gives a digital output representing the time measurement. This initial version of the chip has analog Level 1 and Level 2 storage locations for data sparsification. Two separate fabrication runs resulted in chips that can measure intervals from 8 to 24 ns with approximately 108 ps/LSB resolution. When digital logic is added to count the reference clock, time resolutions of approximately 108 ps could be obtained over time intervals of approximately 1 s.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"32 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":"115213449","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.1992.301307
H. Gonzalez, E. Barsotti, S. Zimmerman, M. Nomachi, O. Sasaki
The authors describe high-speed communication links and protocols of interest for high-energy physics data acquisition systems. The protocols covered are High Performance Parallel Interface (HIPPI), Serial HIPPI, Fibre Channel (FC), and Scalable Coherent Interface (SCI). The initial work required to implement an SDC (Solenoidal Detector Collaboration)-like data acquisition system is also described.<>
{"title":"A comparison of high-speed data links, their commercial support and ongoing R&D activities","authors":"H. Gonzalez, E. Barsotti, S. Zimmerman, M. Nomachi, O. Sasaki","doi":"10.1109/NSSMIC.1992.301307","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301307","url":null,"abstract":"The authors describe high-speed communication links and protocols of interest for high-energy physics data acquisition systems. The protocols covered are High Performance Parallel Interface (HIPPI), Serial HIPPI, Fibre Channel (FC), and Scalable Coherent Interface (SCI). The initial work required to implement an SDC (Solenoidal Detector Collaboration)-like data acquisition system is also described.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"146 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":"115242387","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.1992.301078
Z. Cao, B. Tsui
Multifocal cone-beam collimation has been proposed for cardiac SPECT (single photon emission computed tomography) imaging to increase sensitivity over the heart without truncation of activity distribution in the chest. An accurate and efficient algorithm has been derived for multifocal fan-beam SPECT reconstruction and has been extended to multifocal cone-beam SPECT reconstruction. In the multifocal fan-beam algorithm, the projection data were weighted and filtered for every discrete distance from the detector plane, and then the filtered data were interpolated for a given image point in the backprojection. Thus, the backprojection was carried out only once at a projection view. The multifocal cone-beam algorithm was evaluated using the simulated 3-D Defrise slab phantom and the 3-D Shepp-Logan head phantom. In addition, a preliminary study to evaluate the multifocal cone-beam collimator was performed, in which effects of the focal length distribution and the radius-of-rotation (ROR) on the reconstructed image quality were examined. The image quality was improved with decreased ROR.<>
{"title":"A practical reconstruction algorithm for multifocal cone beam SPECT","authors":"Z. Cao, B. Tsui","doi":"10.1109/NSSMIC.1992.301078","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301078","url":null,"abstract":"Multifocal cone-beam collimation has been proposed for cardiac SPECT (single photon emission computed tomography) imaging to increase sensitivity over the heart without truncation of activity distribution in the chest. An accurate and efficient algorithm has been derived for multifocal fan-beam SPECT reconstruction and has been extended to multifocal cone-beam SPECT reconstruction. In the multifocal fan-beam algorithm, the projection data were weighted and filtered for every discrete distance from the detector plane, and then the filtered data were interpolated for a given image point in the backprojection. Thus, the backprojection was carried out only once at a projection view. The multifocal cone-beam algorithm was evaluated using the simulated 3-D Defrise slab phantom and the 3-D Shepp-Logan head phantom. In addition, a preliminary study to evaluate the multifocal cone-beam collimator was performed, in which effects of the focal length distribution and the radius-of-rotation (ROR) on the reconstructed image quality were examined. The image quality was improved with decreased ROR.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"271 4 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":"124251682","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.1992.301343
P. Pollak, J. McCarthy, D. P. White
Specifying precision magnet power supplies for accelerators can be an arduous and confusing task. The magnet supplies discussed comprise supplies which power dipoles, quadrupoles, and higher order correction magnets as opposed to pulsed septa and kickers. Because power supplies form the foundation of good control of particle beams, it becomes critical that care is taken to remove all possible ambiguity from the specifications. Many times this ambiguity is due to confusion over the basic terms used in the specifications. Different specifications interchangeably use terms like regulation, stability, and accuracy. The authors discuss those terms and parameters which are related to correctly specifying the requested current or voltage and the actual current or voltage.<>
{"title":"Definitions for power supply specification","authors":"P. Pollak, J. McCarthy, D. P. White","doi":"10.1109/NSSMIC.1992.301343","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301343","url":null,"abstract":"Specifying precision magnet power supplies for accelerators can be an arduous and confusing task. The magnet supplies discussed comprise supplies which power dipoles, quadrupoles, and higher order correction magnets as opposed to pulsed septa and kickers. Because power supplies form the foundation of good control of particle beams, it becomes critical that care is taken to remove all possible ambiguity from the specifications. Many times this ambiguity is due to confusion over the basic terms used in the specifications. Different specifications interchangeably use terms like regulation, stability, and accuracy. The authors discuss those terms and parameters which are related to correctly specifying the requested current or voltage and the actual current or voltage.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"10 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":"121043842","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.1992.301288
V. Jordanov, G. Knoll
A digital pulse processor with improved differential linearity and reduced dead time has been designed. The circuit uses an 8-b flash ADC (analog-to-digital converter) running at 36 MHz and continually sampling the signal from the preamplifier or shaping amplifier. The digitized signal is then processed by a digital moving averager. A digital peak detector is used for measuring the amplitude of the shaped pulses. A novel, threshold-free circuit has been designed that combines both the moving average and peak detection functions. The circuit also provides a timing signal with an uncertainty of one sampling period. The number of the averaged samples (equivalent to the shaping time constant) is digitally controlled. The resolution of the processor is limited by the finite ADC resolution and the finite sampling frequency. Increasing the sampling frequency should improve the resolution in pulse height analysis and the timing precision.<>
{"title":"Digital pulse processor using moving average technique","authors":"V. Jordanov, G. Knoll","doi":"10.1109/NSSMIC.1992.301288","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301288","url":null,"abstract":"A digital pulse processor with improved differential linearity and reduced dead time has been designed. The circuit uses an 8-b flash ADC (analog-to-digital converter) running at 36 MHz and continually sampling the signal from the preamplifier or shaping amplifier. The digitized signal is then processed by a digital moving averager. A digital peak detector is used for measuring the amplitude of the shaped pulses. A novel, threshold-free circuit has been designed that combines both the moving average and peak detection functions. The circuit also provides a timing signal with an uncertainty of one sampling period. The number of the averaged samples (equivalent to the shaping time constant) is digitally controlled. The resolution of the processor is limited by the finite ADC resolution and the finite sampling frequency. Increasing the sampling frequency should improve the resolution in pulse height analysis and the timing precision.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"28 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":"127079275","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.1992.301261
K. Anraku, S. Inaba, M. Imori
The authors describe a low-power CAMAC analog-to-digital converter (ADC) module with fast zero suppression developed for high-rate data acquisition on a balloon-borne detector. The module incorporates 16 charge-to-voltage converter (QVC) channels in single CAMAC width. Each channel has its individual ADC. Current input signals are digitized simultaneously. Then a microprogrammed sequencer scans the ADC outputs and stores the digitized data when the outputs are greater than prescribed thresholds. The data scan is completed within 18 mu s, which depends on the number of hit channels. The QVC circuit was optimized by a simulation program on a workstation in order to reduce the temperature dependence.<>
{"title":"Low power ADC with fast zero suppression for a balloon-borne experiment","authors":"K. Anraku, S. Inaba, M. Imori","doi":"10.1109/NSSMIC.1992.301261","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301261","url":null,"abstract":"The authors describe a low-power CAMAC analog-to-digital converter (ADC) module with fast zero suppression developed for high-rate data acquisition on a balloon-borne detector. The module incorporates 16 charge-to-voltage converter (QVC) channels in single CAMAC width. Each channel has its individual ADC. Current input signals are digitized simultaneously. Then a microprogrammed sequencer scans the ADC outputs and stores the digitized data when the outputs are greater than prescribed thresholds. The data scan is completed within 18 mu s, which depends on the number of hit channels. The QVC circuit was optimized by a simulation program on a workstation in order to reduce the temperature dependence.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"97 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":"127183480","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.1992.301201
T. Ohsugi, Y. Iwata, H. Ohyama, M. Okada, T. Ohmoto, Y. Unno, T. Kohriki, N. Tamura, H. Miyata, M. Higuchi, K. Niwa, M. Nakamura, Y. Nagashima, M. Daigo, A. Murakami, S. Kobayashi, K. Yamamoto, K. Yamamura, Y. Muramaatsu
A full-size, double-sided, AC coupling sensor for the SDC central tracker was fabricated. The bias feeding resistor for each strip on both surfaces was implemented by a poly-Si line. The resistance was well controlled within a design value which is good enough to feed uniform bias to each strip. The ohmic-contact strip isolation was attained by inserting a p/sup +/ channel between n/sup +/ strips. The readout capacitance was minimized by making a narrow strip on the p/sup +/ side and by inserting a wide isolation p/sup +/ channel in the n/sup +/ strip side. The capacitance is measured to be 0.8 pF/cm on the p/sup +/ strip side and 1.13 pF/cm on the n/sup +/ strip side. The junction edge breakdown voltage has been pushed up to more than 150 V by an Al strip narrower than the implanted strip width.<>
{"title":"Prototype double-sided silicon sensor (DSSS) for SDC detector","authors":"T. Ohsugi, Y. Iwata, H. Ohyama, M. Okada, T. Ohmoto, Y. Unno, T. Kohriki, N. Tamura, H. Miyata, M. Higuchi, K. Niwa, M. Nakamura, Y. Nagashima, M. Daigo, A. Murakami, S. Kobayashi, K. Yamamoto, K. Yamamura, Y. Muramaatsu","doi":"10.1109/NSSMIC.1992.301201","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301201","url":null,"abstract":"A full-size, double-sided, AC coupling sensor for the SDC central tracker was fabricated. The bias feeding resistor for each strip on both surfaces was implemented by a poly-Si line. The resistance was well controlled within a design value which is good enough to feed uniform bias to each strip. The ohmic-contact strip isolation was attained by inserting a p/sup +/ channel between n/sup +/ strips. The readout capacitance was minimized by making a narrow strip on the p/sup +/ side and by inserting a wide isolation p/sup +/ channel in the n/sup +/ strip side. The capacitance is measured to be 0.8 pF/cm on the p/sup +/ strip side and 1.13 pF/cm on the n/sup +/ strip side. The junction edge breakdown voltage has been pushed up to more than 150 V by an Al strip narrower than the implanted strip width.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"26 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":"124894456","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.1992.301477
L. Antonuk, W. Huang, K. Lam, E. Morton, R. Haken, J. Yorkston, N. Clinthorne
The concept of composite imaging detectors in which a flat-panel array precedes a second level of detection is presented. In radiotherapy, a dual-energy X-ray projection imager would consist of a pair of stacked, flat-panel imagers. The upper detection of level would consist of a flat-panel array with an overlying X-ray converter and would serve as a diagnostic imager. The lower detection level would consist of a second array with an overlying metal sheet/phosphor screen converter and would serve as a megavoltage imager. Such a composite imager would be of significant assistance in helping to resolve the patient localization problem in megavoltage radiotherapy by facilitating the correlation of patient anatomy obtained with diagnostic images with the position of the megavoltage portal field. In a second realization of a composite imager, a flat-panel array placed directly over the crystal in a SPECT (single photon emission computed tomography) camera, or within the detector ring of a PET (positron emission tomography) scanner, would allow the simultaneous collection of emission and transmission projection data.<>
{"title":"Thin-film, flat-panel, composite detectors for projection and tomographic imaging","authors":"L. Antonuk, W. Huang, K. Lam, E. Morton, R. Haken, J. Yorkston, N. Clinthorne","doi":"10.1109/NSSMIC.1992.301477","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301477","url":null,"abstract":"The concept of composite imaging detectors in which a flat-panel array precedes a second level of detection is presented. In radiotherapy, a dual-energy X-ray projection imager would consist of a pair of stacked, flat-panel imagers. The upper detection of level would consist of a flat-panel array with an overlying X-ray converter and would serve as a diagnostic imager. The lower detection level would consist of a second array with an overlying metal sheet/phosphor screen converter and would serve as a megavoltage imager. Such a composite imager would be of significant assistance in helping to resolve the patient localization problem in megavoltage radiotherapy by facilitating the correlation of patient anatomy obtained with diagnostic images with the position of the megavoltage portal field. In a second realization of a composite imager, a flat-panel array placed directly over the crystal in a SPECT (single photon emission computed tomography) camera, or within the detector ring of a PET (positron emission tomography) scanner, would allow the simultaneous collection of emission and transmission projection data.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"99 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":"124939447","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.1992.301140
R. Olsher
Because of aluminum oxide's significant advantage in sensitivity over LiF, minimal fading characteristics, and ease of processing, aluminum oxide thermoluminescent dosimeters (TLDs) are being phased in at Los Alamos for environmental monitoring of photon radiation. The new environmental dosimeter design consists of a polyethylene holder, about 0.5 cm thick, loaded with a stack of four aluminum oxide TLD chips, each 1 mm thick and 5 mm in diameter. As part of the initial evaluation of the new design, the photon energy response of the dosimeter was calculated over the range from 10 keV to 1 MeV. Specific goals of the analysis included the determination of individual chip response in the stack, assessment of the response variation due to TLD material (i.e., LiF versus Al/sub 2/O/sub 3/), and the effect of copper filtration in flattening the response.<>
{"title":"Photon energy response of an aluminum oxide TLD environmental dosimeter","authors":"R. Olsher","doi":"10.1109/NSSMIC.1992.301140","DOIUrl":"https://doi.org/10.1109/NSSMIC.1992.301140","url":null,"abstract":"Because of aluminum oxide's significant advantage in sensitivity over LiF, minimal fading characteristics, and ease of processing, aluminum oxide thermoluminescent dosimeters (TLDs) are being phased in at Los Alamos for environmental monitoring of photon radiation. The new environmental dosimeter design consists of a polyethylene holder, about 0.5 cm thick, loaded with a stack of four aluminum oxide TLD chips, each 1 mm thick and 5 mm in diameter. As part of the initial evaluation of the new design, the photon energy response of the dosimeter was calculated over the range from 10 keV to 1 MeV. Specific goals of the analysis included the determination of individual chip response in the stack, assessment of the response variation due to TLD material (i.e., LiF versus Al/sub 2/O/sub 3/), and the effect of copper filtration in flattening the response.<<ETX>>","PeriodicalId":447239,"journal":{"name":"IEEE Conference on Nuclear Science Symposium and Medical Imaging","volume":"99 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":"123665251","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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