Pub Date : 2000-10-15DOI: 10.1109/NSSMIC.2000.949922
A. Andronic, H. Appelshauser, C. Blume, P. Braun-Munzinger, G. Catanescu, M. Ciobanu, H. Daues, A. Devismes, C. Finck, N. Herrmann, T. Lister, T. Mahmoud, T. Peitzmann, M. Petrovici, A. Reischl, K. Reygers, R. Santo, R. Schulze, S. Sedykh, R. Simon, J. Stachel, H. Stelzer, J. Wessels, O. Winckelmann, C. Xu
A Transition Radiation Detector (TRD) has been designed to improve the electron identification and trigger capability of the ALICE experiment at the Large Hadron Collider (LHC) at CERN. We present results from tests of a prototype of the TRD concerning pion rejection for different methods of analysis over a momentum range from 0.9 to 2.4 GeV/c. We investigate the performance of different radiator types, composed of foils, fibres and foams.
{"title":"Prototype tests for the ALICE transition radiation detector","authors":"A. Andronic, H. Appelshauser, C. Blume, P. Braun-Munzinger, G. Catanescu, M. Ciobanu, H. Daues, A. Devismes, C. Finck, N. Herrmann, T. Lister, T. Mahmoud, T. Peitzmann, M. Petrovici, A. Reischl, K. Reygers, R. Santo, R. Schulze, S. Sedykh, R. Simon, J. Stachel, H. Stelzer, J. Wessels, O. Winckelmann, C. Xu","doi":"10.1109/NSSMIC.2000.949922","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949922","url":null,"abstract":"A Transition Radiation Detector (TRD) has been designed to improve the electron identification and trigger capability of the ALICE experiment at the Large Hadron Collider (LHC) at CERN. We present results from tests of a prototype of the TRD concerning pion rejection for different methods of analysis over a momentum range from 0.9 to 2.4 GeV/c. We investigate the performance of different radiator types, composed of foils, fibres and foams.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124805690","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949234
M. Chen, R. Jaszczak, J. Bowsher, D. Gilland
An experimental phantom study was performed to evaluate cardiac uniformity, contrast and SNR for two clinical cardiac SPECT imaging protocols: adjacent dual-head 180/spl deg/ and triple-head 360/spl deg/ scans. One head of a SPECT camera was used to acquire 180/spl deg/ and 360/spl deg/ projections with different times per step to simulate the clinical case where dual-head 180/spl deg/ and triple-head 360/spl deg/ each takes a total of 20 minutes. Scans were acquired with no lesion, anterior lesion and posterior lesion in the myocardium. Maximum a posteriori (MAP) reconstruction was done by Iterative Coordinate Descent (ICD) algorithm using a quadratic convex prior. The L-curve method was used to obtain the prior strength. Images both with attenuation and scatter correction (ASC) and without ASC were compared. The 180/spl deg/ scan shows an intensity decrease in anterior apical and posterior basal regions. The 360/spl deg/ scan shows an intensity decrease in the posterior wall. For the anterior lesion the 180/spl deg/ scan has slightly better contrast while for the posterior lesion the 360/spl deg/ scan has slightly better contrast. In conclusion, the difference between the 180/spl deg/ and 360/spl deg/ scans is subtle and the comparison results depend on the lesion position and the view angle of the heart. A receiver operating characteristic (ROC) study of 180/spl deg/ vs. 360/spl deg/ acquisition designed based on these characterizations of contrast, uniformity and noise will be necessary to evaluate overall performance.
{"title":"An evaluation of cardiac uniformity, contrast and SNR with dual-head 180 degree and triple-head 360 degree SPECT scans","authors":"M. Chen, R. Jaszczak, J. Bowsher, D. Gilland","doi":"10.1109/NSSMIC.2000.949234","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949234","url":null,"abstract":"An experimental phantom study was performed to evaluate cardiac uniformity, contrast and SNR for two clinical cardiac SPECT imaging protocols: adjacent dual-head 180/spl deg/ and triple-head 360/spl deg/ scans. One head of a SPECT camera was used to acquire 180/spl deg/ and 360/spl deg/ projections with different times per step to simulate the clinical case where dual-head 180/spl deg/ and triple-head 360/spl deg/ each takes a total of 20 minutes. Scans were acquired with no lesion, anterior lesion and posterior lesion in the myocardium. Maximum a posteriori (MAP) reconstruction was done by Iterative Coordinate Descent (ICD) algorithm using a quadratic convex prior. The L-curve method was used to obtain the prior strength. Images both with attenuation and scatter correction (ASC) and without ASC were compared. The 180/spl deg/ scan shows an intensity decrease in anterior apical and posterior basal regions. The 360/spl deg/ scan shows an intensity decrease in the posterior wall. For the anterior lesion the 180/spl deg/ scan has slightly better contrast while for the posterior lesion the 360/spl deg/ scan has slightly better contrast. In conclusion, the difference between the 180/spl deg/ and 360/spl deg/ scans is subtle and the comparison results depend on the lesion position and the view angle of the heart. A receiver operating characteristic (ROC) study of 180/spl deg/ vs. 360/spl deg/ acquisition designed based on these characterizations of contrast, uniformity and noise will be necessary to evaluate overall performance.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124823568","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949121
S. Normand, B. Mouanda, S. Haan, M. Louvel
Neutron detection research using plastic scintillators has recently led to instrument development for several applications and particularly for nuclear material characterization. In particular, plastic scintillators exhibit a fast time response and a high efficiency for fast neutrons spectrometry. The use of boron loaded, plastic scintillators has been also proposed in order to reduce dead time for fission neutron coincidence counting. We report here on fabrication of a new and low cost boron loaded plastic scintillator. Further, a simulation study was performed, including light production and transport in this kind of scintillator. Its characteristics have been measured in terms of light response, photon and neutron induced signals. An experiment has been carried out using the ion beam of a Van de Graaff accelerator at Saclay so as to determine the Birks' parameters of the scintillators. These parameters were obtained for proton (between 1 to 2 MeV) and alpha particles (between 3.35 MeV and 5.4 MeV). The correlation between the experimental data and the simulation predictions has been studied for the neutron response of these scintillators. In addition, the performance of this scintillator are compared with those of commercially available boron loaded plastic scintillator (BC454 from Bicron, Newbury).
使用塑料闪烁体的中子探测研究最近导致了几种应用的仪器开发，特别是用于核材料表征。特别是，塑料闪烁体具有快速的时间响应和高效的快中子光谱测定。为了减少裂变中子符合计数的死亡时间，还提出了使用载硼的塑料闪烁体。本文报道了一种新型低成本载硼塑料闪烁体的制备。在此基础上，对该闪烁体的光产生和输运进行了模拟研究。从光响应、光子和中子诱导信号等方面测量了其特性。利用萨克雷Van de Graaff加速器的离子束进行了实验，以确定闪烁体的Birks参数。这些参数适用于质子(1 ~ 2 MeV)和α粒子(3.35 ~ 5.4 MeV)。对这些闪烁体的中子响应进行了实验数据与模拟预测的相关性研究。此外，还将该闪烁体的性能与市售的硼塑料闪烁体(来自Bicron, Newbury的BC454)进行了比较。
{"title":"Study of a new boron loaded plastic scintillator","authors":"S. Normand, B. Mouanda, S. Haan, M. Louvel","doi":"10.1109/NSSMIC.2000.949121","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949121","url":null,"abstract":"Neutron detection research using plastic scintillators has recently led to instrument development for several applications and particularly for nuclear material characterization. In particular, plastic scintillators exhibit a fast time response and a high efficiency for fast neutrons spectrometry. The use of boron loaded, plastic scintillators has been also proposed in order to reduce dead time for fission neutron coincidence counting. We report here on fabrication of a new and low cost boron loaded plastic scintillator. Further, a simulation study was performed, including light production and transport in this kind of scintillator. Its characteristics have been measured in terms of light response, photon and neutron induced signals. An experiment has been carried out using the ion beam of a Van de Graaff accelerator at Saclay so as to determine the Birks' parameters of the scintillators. These parameters were obtained for proton (between 1 to 2 MeV) and alpha particles (between 3.35 MeV and 5.4 MeV). The correlation between the experimental data and the simulation predictions has been studied for the neutron response of these scintillators. In addition, the performance of this scintillator are compared with those of commercially available boron loaded plastic scintillator (BC454 from Bicron, Newbury).","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129557189","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949297
S. Chapuy, Z. Dimcovski, M. Pachoud, F. Terrier, J. Valley, F. R. Verdun
The aim of this study is to present our first results in industrial nondestructive testing obtained with a real-time digital imaging device, X-View, based on active matrix flat panel imager technology. X-View consists of X-ray converters, arrays of amorphous silicon (a-Si:H) thin film transistors (TFT) and photodiodes, a fast realtime electronic system for readout and digitization of images and appropriate computer tools for control, realtime image treatment data representation and off-line analysis. Different tests objects were used for qualitative analysis. X-View is capable of producing up to 10 frames per second and with a pixel size up to 100 /spl mu/m. Results show: easy handling of the device, its compactness and simplicity in operation; a wide dynamic range and lack of blooming; a high frame rate. The rapid image capture permits to install the system on a production site-the images are directly displayed on-line, on a PC monitor and archived in a digital form for radiography and radioscopy procedures. The flat panel X-ray imager based on amorphous silicon technology implemented in standard X-ray industrial equipment, permits acquisition of real-time images of excellent quality.
{"title":"Real-time flat panel pixel imaging system in X-ray detection","authors":"S. Chapuy, Z. Dimcovski, M. Pachoud, F. Terrier, J. Valley, F. R. Verdun","doi":"10.1109/NSSMIC.2000.949297","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949297","url":null,"abstract":"The aim of this study is to present our first results in industrial nondestructive testing obtained with a real-time digital imaging device, X-View, based on active matrix flat panel imager technology. X-View consists of X-ray converters, arrays of amorphous silicon (a-Si:H) thin film transistors (TFT) and photodiodes, a fast realtime electronic system for readout and digitization of images and appropriate computer tools for control, realtime image treatment data representation and off-line analysis. Different tests objects were used for qualitative analysis. X-View is capable of producing up to 10 frames per second and with a pixel size up to 100 /spl mu/m. Results show: easy handling of the device, its compactness and simplicity in operation; a wide dynamic range and lack of blooming; a high frame rate. The rapid image capture permits to install the system on a production site-the images are directly displayed on-line, on a PC monitor and archived in a digital form for radiography and radioscopy procedures. The flat panel X-ray imager based on amorphous silicon technology implemented in standard X-ray industrial equipment, permits acquisition of real-time images of excellent quality.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127528601","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949192
S. Moore, G. El Fakhri, R. Badawi, A. D. Van den Abbeele, R. Zimmerman
The authors estimated the detectability of spheres of different sizes but equal activity contrast, embedded in a clinically realistic phantom in order to compare two-dimensional (2D) and three-dimensional (3D) whole-body (WB) PET imaging for a relevant diagnostic task. Five plastic spheres with inside diameters of 0.8 to 3.4 cm, containing 74 kBq/ml of Ge-68, were placed in an anthropomorphic torso phantom. The background organs contained F-18 activity concentrations in appropriate physiologic proportions, as did a head phantom positioned outside the field of view (FOV) of the authors' ECAT-HR+ system. The phantom was scanned for 9 hours at 1 bed position as the F-18 decayed from 97 to 3.2 kBq/ml. The authors obtained 10, 1-minute scans for each activity contrast level, alternating among 3 acquisitions: 2D mode with standard maximum ring difference (MRD=7), standard 3D mode (MRD=22), and 3D mode with MRD=13 (3D*). Images from 2D and 3D acquisitions were reconstructed by filtered backprojection and 3D reprojection (3DRP); 3D data were also reconstructed by FBP after Fourier rebinning (FORE+FBP). Sphere detectability was estimated using non-prewhitening (NPW) matched filtering to compute the detection signal-to-noise ratio, NPW SNR. In almost all cases, NPW-SNR was greater for 3D or 3D* than for 2D, although 2D outperformed 3D with 3DRP reconstruction at the earliest time points for 2 spheres located near opposite ends of the axial FOV; FORE+FBP reconstruction significantly improved the detectability of these spheres, compared to 3DRP, and demonstrated the expected near equivalence of 3D and 3D* data from spheres near the ends of the FOV. The authors' results were not predictable from global NEC considerations alone.
{"title":"Relative lesion detectability in 3D vs. 2D dedicated multi-ring PET","authors":"S. Moore, G. El Fakhri, R. Badawi, A. D. Van den Abbeele, R. Zimmerman","doi":"10.1109/NSSMIC.2000.949192","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949192","url":null,"abstract":"The authors estimated the detectability of spheres of different sizes but equal activity contrast, embedded in a clinically realistic phantom in order to compare two-dimensional (2D) and three-dimensional (3D) whole-body (WB) PET imaging for a relevant diagnostic task. Five plastic spheres with inside diameters of 0.8 to 3.4 cm, containing 74 kBq/ml of Ge-68, were placed in an anthropomorphic torso phantom. The background organs contained F-18 activity concentrations in appropriate physiologic proportions, as did a head phantom positioned outside the field of view (FOV) of the authors' ECAT-HR+ system. The phantom was scanned for 9 hours at 1 bed position as the F-18 decayed from 97 to 3.2 kBq/ml. The authors obtained 10, 1-minute scans for each activity contrast level, alternating among 3 acquisitions: 2D mode with standard maximum ring difference (MRD=7), standard 3D mode (MRD=22), and 3D mode with MRD=13 (3D*). Images from 2D and 3D acquisitions were reconstructed by filtered backprojection and 3D reprojection (3DRP); 3D data were also reconstructed by FBP after Fourier rebinning (FORE+FBP). Sphere detectability was estimated using non-prewhitening (NPW) matched filtering to compute the detection signal-to-noise ratio, NPW SNR. In almost all cases, NPW-SNR was greater for 3D or 3D* than for 2D, although 2D outperformed 3D with 3DRP reconstruction at the earliest time points for 2 spheres located near opposite ends of the axial FOV; FORE+FBP reconstruction significantly improved the detectability of these spheres, compared to 3DRP, and demonstrated the expected near equivalence of 3D and 3D* data from spheres near the ends of the FOV. The authors' results were not predictable from global NEC considerations alone.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130011880","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949418
B. Jost
The LHCb experiment is the most recently approved of the 4 experiments under construction at CERN's LHC accelerator. It is a special purpose experiment designed to precisely measure the CP violation parameters in the B-B system. Triggering poses special problems since the interesting events containing B-mesons are immersed in a large background of inelastic p-p reactions. We therefore decided to implement a 4 level triggering scheme. The LHCb DAQ system will have to cope with an average trigger rate of /spl sim/40 kHz, after two levels of hardware triggers, and an average event size of /spl sim/150 kB. Thus an event-building network which can sustain an average bandwidth of 6 GB/s is required. A powerful software trigger farm will have to be installed to reduce the rate from the 40 kHz to /spl sim/200 Hz of events written to permanent-storage. In this paper we will concentrate on the networking aspects of the LHCb data acquisition and the control system.
{"title":"The LHCb DAQ system","authors":"B. Jost","doi":"10.1109/NSSMIC.2000.949418","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949418","url":null,"abstract":"The LHCb experiment is the most recently approved of the 4 experiments under construction at CERN's LHC accelerator. It is a special purpose experiment designed to precisely measure the CP violation parameters in the B-B system. Triggering poses special problems since the interesting events containing B-mesons are immersed in a large background of inelastic p-p reactions. We therefore decided to implement a 4 level triggering scheme. The LHCb DAQ system will have to cope with an average trigger rate of /spl sim/40 kHz, after two levels of hardware triggers, and an average event size of /spl sim/150 kB. Thus an event-building network which can sustain an average bandwidth of 6 GB/s is required. A powerful software trigger farm will have to be installed to reduce the rate from the 40 kHz to /spl sim/200 Hz of events written to permanent-storage. In this paper we will concentrate on the networking aspects of the LHCb data acquisition and the control system.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130017924","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949961
J. Cardoso, V. Amorim, R. Bastos, R. Madeira, J. Basilio Simoes, C. Correia
A very, low-cost portable Multichannel Analyzer (MCA) built with off-the-shelf commercial components is presented. Built around an universal microcontroller based platform for portable instruments, previously developed in our group, this intelligent portable MCA is operated by multicell Li-ion batteries and has power and memory autonomy for several hours of spectra collecting. The MCA integrates a basic front-end pulse shape amplifier, a base line restorer, a peak detector and logic control circuitry. The growing of the radiation spectrum can be easily observed on site through a dot-matrix graphic display. To save the acquired data and allow for the configuration of setup parameters, it connects to any host computer through standard USB, IrDA or RS-232 serial interfaces being also prepared to interface a GPS unit. Software application programs in both the portable MCA and the host PC are presented.
{"title":"A very low-cost portable multichannel analyzer","authors":"J. Cardoso, V. Amorim, R. Bastos, R. Madeira, J. Basilio Simoes, C. Correia","doi":"10.1109/NSSMIC.2000.949961","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949961","url":null,"abstract":"A very, low-cost portable Multichannel Analyzer (MCA) built with off-the-shelf commercial components is presented. Built around an universal microcontroller based platform for portable instruments, previously developed in our group, this intelligent portable MCA is operated by multicell Li-ion batteries and has power and memory autonomy for several hours of spectra collecting. The MCA integrates a basic front-end pulse shape amplifier, a base line restorer, a peak detector and logic control circuitry. The growing of the radiation spectrum can be easily observed on site through a dot-matrix graphic display. To save the acquired data and allow for the configuration of setup parameters, it connects to any host computer through standard USB, IrDA or RS-232 serial interfaces being also prepared to interface a GPS unit. Software application programs in both the portable MCA and the host PC are presented.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129019705","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949219
O. Ivanov, V. Potapov, V. Stepanov
In the last decade V.E. Radko has introduced the concept of gamma-ray radar for 3D Compton imaging with a probing beam of 511 keV annihilation gamma-rays from positron emitting radioactive sources. The simultaneous detection with 2 position sensitive detectors of direct, non-scattered quanta and second quanta scattered in the investigated object produce information of density distribution or composition of the object. This new type of gamma-ray imaging system for nondestructive testing may have different applications in flaw detection and studying of structure of opaque objects with one side access. The performance of the system was studied with Monte-Carlo simulation.
{"title":"A simulation of gamma-ray radar performance with different position sensitive detectors","authors":"O. Ivanov, V. Potapov, V. Stepanov","doi":"10.1109/NSSMIC.2000.949219","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949219","url":null,"abstract":"In the last decade V.E. Radko has introduced the concept of gamma-ray radar for 3D Compton imaging with a probing beam of 511 keV annihilation gamma-rays from positron emitting radioactive sources. The simultaneous detection with 2 position sensitive detectors of direct, non-scattered quanta and second quanta scattered in the investigated object produce information of density distribution or composition of the object. This new type of gamma-ray imaging system for nondestructive testing may have different applications in flaw detection and studying of structure of opaque objects with one side access. The performance of the system was studied with Monte-Carlo simulation.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129142900","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949104
F. Javanmardi, G. Wakabayashi, M. Zolfaghari, A. Minuchehr, M. M. Rashid, M. Matoba
A study about readout responses for the inclined strips in position sensitive detectors has been done using theoretical predictions and experimental results. Inclined strips are almost along the displacement direction of incident particles. Rotating conventional strips to near horizontal strips decreases the number of strips by a tangential factor for long length position sensing. In addition to the channel reduction, the inclined strips modify about ten percent (10%) in the readout linearity in comparison to the long length zigzag patterns. There is resolution degradation because of the inherent high sensitivity of these strips to the avalanche size (about 8% of the detector full length). Double peak responses were observed for sensing the positions of the incident particles. Our theoretical predictions and experimental results are discussed.
{"title":"Readout responses of inclined strips in position sensitive detectors","authors":"F. Javanmardi, G. Wakabayashi, M. Zolfaghari, A. Minuchehr, M. M. Rashid, M. Matoba","doi":"10.1109/NSSMIC.2000.949104","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949104","url":null,"abstract":"A study about readout responses for the inclined strips in position sensitive detectors has been done using theoretical predictions and experimental results. Inclined strips are almost along the displacement direction of incident particles. Rotating conventional strips to near horizontal strips decreases the number of strips by a tangential factor for long length position sensing. In addition to the channel reduction, the inclined strips modify about ten percent (10%) in the readout linearity in comparison to the long length zigzag patterns. There is resolution degradation because of the inherent high sensitivity of these strips to the avalanche size (about 8% of the detector full length). Double peak responses were observed for sensing the positions of the incident particles. Our theoretical predictions and experimental results are discussed.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131077252","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 : 2000-10-15DOI: 10.1109/NSSMIC.2000.949168
J. J. Vaquero, M. Desco, J. Pascau, Andrés Santos, I. Lee, J. Seidel, M.V. Green
Spatially registered PET and CT images of the same small animal offer at least three potential advantages over PET alone. First, the CT images should allow accurate, nearly noise-free correction of the PET image data for attenuation. Second, the CT images should permit more certain identification of structures evident in the PET images and third, the CT images provide a priori anatomical information that may be of use with resolution-improving image reconstruction algorithms that model the PET imaging process. Thus far, however, image registration algorithms effective in human studies have not been characterized in the small animal setting. Accordingly, the authors evaluated the ability of the AIR algorithm to accurately register PET F-18 fluoride and F-18 FDG images of the rat skull and brain, respectively, to CT images acquired following each PET imaging session. The AIR algorithm was able to register the bone-to-bone images with a maximum error of less than 1.0 mm. The registration error for the brain-to-brain study, however, was greater (2.4 mm) and required additional steps and user intervention to segment the brain from the head in both data sets before registration. These preliminary results suggest that the AIR algorithm can accurately combine PET and CT images in small animals when the data sets are nearly homologous, but may require additional segmentation steps with increased mis-registration errors when registering disparate, low contrast soft tissue structures.
{"title":"PET and CT image registration of the rat brain and skull using the AIR algorithm","authors":"J. J. Vaquero, M. Desco, J. Pascau, Andrés Santos, I. Lee, J. Seidel, M.V. Green","doi":"10.1109/NSSMIC.2000.949168","DOIUrl":"https://doi.org/10.1109/NSSMIC.2000.949168","url":null,"abstract":"Spatially registered PET and CT images of the same small animal offer at least three potential advantages over PET alone. First, the CT images should allow accurate, nearly noise-free correction of the PET image data for attenuation. Second, the CT images should permit more certain identification of structures evident in the PET images and third, the CT images provide a priori anatomical information that may be of use with resolution-improving image reconstruction algorithms that model the PET imaging process. Thus far, however, image registration algorithms effective in human studies have not been characterized in the small animal setting. Accordingly, the authors evaluated the ability of the AIR algorithm to accurately register PET F-18 fluoride and F-18 FDG images of the rat skull and brain, respectively, to CT images acquired following each PET imaging session. The AIR algorithm was able to register the bone-to-bone images with a maximum error of less than 1.0 mm. The registration error for the brain-to-brain study, however, was greater (2.4 mm) and required additional steps and user intervention to segment the brain from the head in both data sets before registration. These preliminary results suggest that the AIR algorithm can accurately combine PET and CT images in small animals when the data sets are nearly homologous, but may require additional segmentation steps with increased mis-registration errors when registering disparate, low contrast soft tissue structures.","PeriodicalId":445100,"journal":{"name":"2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130561615","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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