1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record最新文献_第4页

An amplifier-shaper-discriminator with baseline restoration for the ATLAS transition radiation tracker 用于ATLAS跃迁辐射跟踪器的基线恢复放大-整形-鉴别器

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504243

B. Bevensee, F. Newcomer, R. Van Berg, H. Williams

引用次数: 32

Improved Bayesian image reconstruction in positron emission tomography 正电子发射断层成像中改进的贝叶斯图像重建

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510468

C. Kao, X. Pan, C. Chen, W. H. Wong

{"title":"Improved Bayesian image reconstruction in positron emission tomography","authors":"C. Kao, X. Pan, C. Chen, W. H. Wong","doi":"10.1109/NSSMIC.1995.510468","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510468","url":null,"abstract":"We extend the Bayesian model (Johnson, Chen, et al., 1990, 1991), previously developed for image reconstruction and restoration, by the introduction of diagonal line sites and the use of symmetrical neighborhood configurations. A computer simulation study was performed to examine the effect of the hyperparameters, the diagonal line sites, and the size of the neighbourhood configuration on the performance of the Bayesian method. We show that for optimal performance, distinct hyperparameters should be used for the intensity sites and line sites. The results also suggested the use of a larger configuration. By comparing the near-optimal restored images, we also demonstrate that the use of diagonal line sites, along with the symmetrical configurations thus made possible, can effectively remove the blocky edge artifacts and produce images of better quality. For image reconstruction applications, in addition to the use of diagonal line sites and symmetrical neighborhood configurations, we suggested using the area-weighted projection/backprojection technique to improve the accuracy of the system response function. Quality of reconstructed images were shown to be improved for both computer simulated and real patient PET data.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132240893","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}

引用次数: 5

A front end electronic design with sliding ADC channels and X-Y decoder for a position sensitive scintillator block array 一种具有滑动ADC通道和X-Y解码器的前端电子设计，用于位置敏感闪烁体块阵列

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510441

W. Wong, Guoji Hu, WeiZhao Lu, K. Hicks, J. Uribe

{"title":"A front end electronic design with sliding ADC channels and X-Y decoder for a position sensitive scintillator block array","authors":"W. Wong, Guoji Hu, WeiZhao Lu, K. Hicks, J. Uribe","doi":"10.1109/NSSMIC.1995.510441","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510441","url":null,"abstract":"This is an electronic design for a position sensitive detector system with a large array of crystal blocks (each block is composed of many crystals). The design goals are parts and space reduction. Each PMT has its fast amplifier and triggered integrator. Nine flash ADC, 3 adders, 2 EPROM and 10 program logic devices are used to determine the scintillation location for an array of 27 PMT and 784 crystals. The fast signals from one or more PMT clusters are summed. The fast summed signals are thresholded and sent to a GAL to determines the probable scintillation zone (several blocks) and to turn on the associated PMT integrators. After integration, the GAL also drives a set of ultra-fast analog switches to connect the flash ADC set (9 units) to the PMT integration channels in the scintillation zone. The 9 ADC output (integrated pulses with good photon statistics) are latched and compared. The comparator result determines which block in the probable zone is firing and the appropriate 4 ADC are selected and bused into a position decoder composed of 3 adders and a EPROM. The EPROM outputs the X-Y position along with the block-address. The circuit is pipelined and driven by a 250 MHz master clock. The maximum event-processing rate for the circuit and a random radiation source is 2/spl times/10/sup 6//sec (with 10:1 randomness allowance).","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133832176","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}

引用次数: 0

Performance of a Compton telescope using position-sensitive germanium detectors 使用位置敏感锗探测器的康普顿望远镜的性能

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504202

B. Phlips, S. Inderhees, R. Kroeger, W. Johnson, R. Kinzer, J. Kurfess, B. Graham, N. Gehrels

引用次数: 13

Radial distributions of /sup 60/Co contaminants surrounding wellbores at the Hanford Site 汉福德油井周围/sup 60/Co污染物的径向分布

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504212

L. Gadeken, W. Madigan, H.D. Smith

{"title":"Radial distributions of /sup 60/Co contaminants surrounding wellbores at the Hanford Site","authors":"L. Gadeken, W. Madigan, H.D. Smith","doi":"10.1109/NSSMIC.1995.504212","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.504212","url":null,"abstract":"The Department of Energy is sponsoring large scale environmental characterization and monitoring efforts at the Hanford Site to determine the properties and movements of plumes containing radioactive contaminants. Halliburton is participating in a Cooperative Research and Development Agreement with DOE-Richland and its contractors to adapt several nuclear borehole geophysical logging systems to the arid Hanford conditions. A number of the more than 4000 Hanford monitoring wells are suitable for various types of logging measurements. In particular, the distributions of gamma-ray-emitting radionuclides can be mapped with spectroscopy instruments. During the demonstration phase of this project gamma ray spectroscopy data were gathered with a Compensated Spectral Natural Gamma sonde in Well W15-7 in the 200-West Area. Using \"whole\" spectrum techniques developed for oil field applications these spectroscopy data reveal information about the radial distribution of /sup 60/Co contaminants. Specifically, below the water table, many of the detected gamma rays originate from /sup 60/Co which appears to be adsorbed onto corroded steel well casing. The relevance of these results to environmental remediation at the Hanford Site is discussed since it appears that some radioactive contamination may be more localized than currently assumed.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131624384","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}

引用次数: 4

A scalable multiprocessor implementation of the reprojection algorithm for volumetric PET imaging 体积PET成像重投影算法的可扩展多处理器实现

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510473

P. Crandall, C. Stearns

引用次数: 13

The effect of pixel geometry on spatial and spectral resolution in a CdZnTe imaging array 像素几何形状对CdZnTe成像阵列空间和光谱分辨率的影响

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504320

J. Eskin, H. Barrett, H. B. Barber, J. Woolfenden

{"title":"The effect of pixel geometry on spatial and spectral resolution in a CdZnTe imaging array","authors":"J. Eskin, H. Barrett, H. B. Barber, J. Woolfenden","doi":"10.1109/NSSMIC.1995.504320","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.504320","url":null,"abstract":"We analyze the various factors contributing to the spatial and spectral resolution of a focal plane imager made from a 25 mm square slab of CdZnTe patterned into an array of pixels. Each pixel is connected to a charge-sensitive preamplifier that integrates the current flowing through the pixel electrode for a frame time of one millisecond. The fraction of charge collected by the integrating circuit is influenced by two trends. Some signal is lost to neighboring pixels due to nonlocalized generation and subsequent diffusion of charge carriers. An opposing phenomenon we term the \"near-field effect\" has a greater influence on charge collection as well as spatial resolution. We show using electrostatic theory that the smaller the pixel dimension, the more electron transport contributes to the induced signal, and the less hole transport matters. The result is an improved pulse-height spectrum with less tailing due to trapped charges. Monte Carlo simulations and measurements on test pixels confirm the improvement in pulse height spectrum with smaller pixel dimension. Numerical calculation of the potential distribution within the detector volume allows us to include the effect of inter-pixel spaces in the simulations.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126593877","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}

引用次数: 32

Development and characterization of zone melt growth GaAs for gamma-ray detectors 伽玛射线探测器用区熔生长GaAs的研制与表征

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504185

S. King, H. Dietrich, R. Henry, D. Katzer, W. Moore, G. Phillips, R. C. Mania

引用次数: 3

Test stand for the Silicon Vertex Detector of the Collider Detector Facility 对撞机探测器设施硅顶点探测器的试验台

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504316

S. Zimmermann, J. Anderson, J. Andresen, E. Barsotti, J. Chramowicz, G. Duerling, M. Gao, H. Gonzalez, B. Haynes, W. Knopf, K. Treptow, D. Walsh, T. Zmuda, T. Huffman, P. Shepard, C. Gay, S. Harder, H. Hill, J. Huth, J. O’Kane, J. Oliver, H. Robins, M. Spiropulu, R. Strohmer, M. Gold, T. Thomas

{"title":"Test stand for the Silicon Vertex Detector of the Collider Detector Facility","authors":"S. Zimmermann, J. Anderson, J. Andresen, E. Barsotti, J. Chramowicz, G. Duerling, M. Gao, H. Gonzalez, B. Haynes, W. Knopf, K. Treptow, D. Walsh, T. Zmuda, T. Huffman, P. Shepard, C. Gay, S. Harder, H. Hill, J. Huth, J. O’Kane, J. Oliver, H. Robins, M. Spiropulu, R. Strohmer, M. Gold, T. Thomas","doi":"10.1109/NSSMIC.1995.504316","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.504316","url":null,"abstract":"A test stand for the next generation of the Silicon Vertex Detector (SVX-II) of the Collider Detector Facility (CDF) at Fermilab has been developed. It is capable of performing cosmic ray, beam, and laser pulsing tests on silicon strip detectors using the new generation of SVX chips. The test stand is composed of a SGI workstation, a VME CPU, the Silicon Test Acquisition and Readout (STAR) board, the Test Fiber Interface Board (TFIB), and the Test Port Card (TPC). The STAR mediates between external stimuli for the different tests and produces appropriate high level commands which are sent to the TFIB. The TFIB, in conjunction with the TPC, translates these commands into the correct logic levels to control the SVX chips. The four modes of operation of the SVX chips are configuration, data acquisition, digitization, and data readout. The data read out from the SVX chips is transferred to the STAR. The STAR can then be accessed by the VME CPU and the SGI workstation for future analyses. The detailed description of this test stand is given.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115361232","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}

引用次数: 1

Modifications to MCNP to provide coincident data files for use in Compton camera geometry studies 修改MCNP，为康普顿相机几何研究提供一致的数据文件

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510399

J. McKisson, D. Henderson, P. Haskins

{"title":"Modifications to MCNP to provide coincident data files for use in Compton camera geometry studies","authors":"J. McKisson, D. Henderson, P. Haskins","doi":"10.1109/NSSMIC.1995.510399","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510399","url":null,"abstract":"Compton camera imaging (CCI) systems have been investigated for a number of applications. Because useful Compton events consist of coincident interactions in two or more detector element cells, a simulation code used must also produce coincidence event data information. While MCNP is an effective and well-tested Monte Carlo code, in its unmodified form it does offer provisions to produce the necessary coincidence data. This paper describes modifications to the MCNP 4A code to enable it to provide a file containing coincident event data from cells of interest for a wide variety of geometries and problems. An alternative to modification, the use of the PTRAC option was first considered and reasons for its rejection are discussed. The approach taken for extracting coincidence information was designed to avoid alteration of the program data or control variables. The modification to MCNP involves intercepting the F8 tally energy accounting data for cells of interest. A description of the modification data structures and data flow are presented. Sample input and output files are presented and limitations of this technique are discussed. The approach to validation of code integrity after modification is also discussed.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115632982","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}

引用次数: 6