2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)最新文献_第3页

Afterpulse effect in SiPM and neutron irradiation studies SiPM后脉冲效应和中子辐照研究

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7430746

E. Garutti, M. Gensch, R. Klanner, M. Ramilli, C. Xu

{"title":"Afterpulse effect in SiPM and neutron irradiation studies","authors":"E. Garutti, M. Gensch, R. Klanner, M. Ramilli, C. Xu","doi":"10.1109/NSSMIC.2014.7430746","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430746","url":null,"abstract":"Radiation hard SiPMs are strongly demanded for the application in the LHC detectors. Examples are the LHCb fiber tracker, the CMS outer calorimeter, and for future application in detectors for ILC, as well as for space detectors. Radiation doses up to a few times 1012neq/cm2 are expected at the positions of the SiPMs at LHC. Dedicated studies on the effects of radiation on SiPMs are required to improve the performance of the existing devices. The effects of proton and neutron radiation on silicon crystals are well known. Macroscopically, they lead to the reduction of the signal, the increase of noise and the alteration of the electric field. In SiPMs defects formed in the vicinity of the narrow multiplication region (up to 2-3 μm from the surface) have an impact on the device operation. In this paper we focus on the investigation of various noise sources, generation and recombination (or dark noise), noise induced by de-trapping (or afterpulses), and optical cross-talk between pixels. We attempt to establish a method to separate the afterpulse contribution of noise and determine the de-trapping time constant and the afterpulse probability as a function of temperature and excess bias voltage. We found that afterpulses in a particular KETEK SiPM can be described with the use of one characteristic de-trapping time constant of the order of 75 ns. We present a series of irradiation studies performed on few samples of SiPMs from KETEK exposed to a neutron fluence of 1-10×1010neq/cm2. After such irradiations, while the SiPM static parameters do not change significantly, the noise increases by 3 orders of magnitude, posing serious limitations to their usage. Unfortunately, with such an increase we have not managed to disentangle the afterpulse contribution from the noise.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116098123","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

Fabrication of present-generation microstructured semiconductor neutron detectors 当代微结构半导体中子探测器的制造

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7431177

T. Ochs, S. Bellinger, R. Fronk, L. C. Henson, C. J. Rietcheck, T. Sobering, R. Taylor, D. Mcgregor

引用次数: 4

Development of MR insertable small animal PET utilizing high resolution event positioning circuit and charge signal transmission approach 基于高分辨率事件定位电路和电荷信号传输方法的小动物磁共振可插入PET的研制

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7430867

Sangwon Lee, Yong Choi, Jin Ho Jung, Sangsu Kim, Jaewoo Choi

引用次数: 0

Geant4 and beyond: Precision physics modeling and validation Geant4及以上:精确的物理建模和验证

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7430826

T. Basaglia, M. Batič, M. Begalli, M. Han, S. Hauf, G. Hoff, Chan Hyeong Kim, Han Sung Kim, Sung Hun Kim, M. Kuster, M. Pia, P. Saracco, G. Weidenspointer

引用次数: 0

Simulations, testing and results for the pixelation of LYSO crystals for gamma detectors using SSLE techniques 利用SSLE技术对伽马探测器LYSO晶体像素化的模拟、测试和结果

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7430866

G. Konstantinou, R. Chil, J. Ripoll, J. Udías, M. Desco, J. Vaquero

{"title":"Simulations, testing and results for the pixelation of LYSO crystals for gamma detectors using SSLE techniques","authors":"G. Konstantinou, R. Chil, J. Ripoll, J. Udías, M. Desco, J. Vaquero","doi":"10.1109/NSSMIC.2014.7430866","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430866","url":null,"abstract":"One of the most common topologies for the scintillator crystals used in gamma radiation detectors for PET scanners is pixelation. The size of these pixels, the crystal surface treatment and the reflector thickness inserted between crystals directly affects the energy and the spatial resolution as well as the sensitivity of the detector. The fabrication of pixels is laborious, complex and expensive. Here we investigate the possibility of creating pixels within monolithic LYSO scintillators crystals using the proven technique of sub-surface laser engraving with a Nd:YAG laser. To evaluate possible designs considering the limitations of the engraving procedure, we used the simulation software GAMOS to analyze the light propagation inside the crystals engraved with a variety of patterns. We carried out different experimental procedures, including microscopy and laser reflectometry to assess the relative reflective quality of the engraved surfaces. We compared the results of different engraving procedures to a reference reflector commonly used in this type of pixelated crystal matrices. We have configured different engraved surfaces with variable transparency in several pixel geometries including depth-of-interaction encoding patterns. Our results demonstrate that pixels engraved with this method can also be configured to compensate for the multiplexed readout penalties, and at the same time preserve the detector performance requirements. Such modifications of the engraving pattern takes place at practically no cost and constitute a highly promising solution for industrial fabrication, reducing substantially the cost of the detector.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128556308","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: 3

Image reconstruction using tetrahedral voxels: A list mode implementation for awake animal imaging 使用四面体体素的图像重建:清醒动物成像的列表模式实现

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7431025

J. Gillam, G. Angelis, W. Ryder, S. Meikle

{"title":"Image reconstruction using tetrahedral voxels: A list mode implementation for awake animal imaging","authors":"J. Gillam, G. Angelis, W. Ryder, S. Meikle","doi":"10.1109/NSSMIC.2014.7431025","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431025","url":null,"abstract":"Reliable interpretation of results from pre-clinical Emission Tomography studies is often hampered by the requirement that the animal be anesthetised, affecting certain neuro-transmission systems and cerebral blood flow. Animal tracking and motion compensation techniques have been exploited to account for that rigid motion associated with head movement - allowing brain imaging in small animals. However, rigid motion cannot be assumed for extra cranial activity. Tetrahedral mesh approaches have been applied in cardiac reconstruction to account for non-rigid motion in clinical environments. In this investigation a list-mode approach to calculation of the elements of the system matrix using a tetrahedral image space is developed and evaluated by applying rigid motion compensation to both simulated and experimental data. Experimental data for which only rigid motion was applied were used to demonstrate the application of variable voxel-size over the image space. A simple small animal model comprising rigid (head) and non-rigid (body) motion was developed and the resulting voxelised sources were simulated using GATE. Motion compensation based on rigid transforms allowed targeted voxel sampling and demonstrates the impact of the non-rigid motion of activity estimates. The tetrahedral mesh should allow future investigations to extend correction to also include non-rigid estimates of small animal motion.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128711952","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

Capacitor based multiplexing circuit for silicon photomultiplier array readout 基于电容的硅光电倍增管阵列读出复用电路

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7431219

Xishan Sun, K. Lou, Y. Shao

{"title":"Capacitor based multiplexing circuit for silicon photomultiplier array readout","authors":"Xishan Sun, K. Lou, Y. Shao","doi":"10.1109/NSSMIC.2014.7431219","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431219","url":null,"abstract":"Several different multiplexing readout methods have been investigated for reading out silicon photomultiplier (SiPM) arrays. However, it is still challenging by using these methods to maintain signal integrity for overall good signal and imaging performance while reducing the number of readout and processing channels. One common issue to resistor based multiplexing method is the position-dependent timing shift among different channels, which can in principle be calibrated and corrected but add complexity to the detector calibration and operation process, and can be very difficult to apply for a practical PET system for routine imaging applications. To solve such and other problems, we explored a capacitor-based multiplexing method for our PET detector to read SiPM with a common cathode which has not been addressed previously. To achieve good detector performance, we required output signal without undershot/overshot suited for excellent charge integration, and without timing shift among different channels. The design applies a capacitor network to divide the charge of signals from a SiPM into two branches, with the division of charge based on the position of the SiPM in the network. Only one capacitor value is needed. The number of readout channels can be reduced from N×N to 2N. Evaluation circuit was tested with pulsed signals and a practical PET detector which consisted of an 8×8 SiPM array and LYSO scintillator array. The results showed that signal rise and fall times from different channels were the similar, no output signal undershot, and no timing shift among different channels. The resistive and capacitive multiplexing methods were compared for their noise level, energy resolution, rise time, and timing resolution as function of channel numbers. Capacitive multiplexing method shows better noise and timing performance with much better timing and energy consistent from all detector area. A PCB circuit board with capacitor multiplexing has been developed for PET detector applications.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129005427","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

3-D photon impact determination using fitting approaches to the Light Distribution 利用光分布拟合方法确定三维光子冲击

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7430889

P. Conde, Antonio J. González, L. Hernández, P. Bellido, E. Crespo, A. Iborra, L. Moliner, J. Rigla, M. Rodríguez-Álvarez, F. Sánchez, M. Seimetz, A. Soriano, L. Vidal, J. Benlloch

{"title":"3-D photon impact determination using fitting approaches to the Light Distribution","authors":"P. Conde, Antonio J. González, L. Hernández, P. Bellido, E. Crespo, A. Iborra, L. Moliner, J. Rigla, M. Rodríguez-Álvarez, F. Sánchez, M. Seimetz, A. Soriano, L. Vidal, J. Benlloch","doi":"10.1109/NSSMIC.2014.7430889","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430889","url":null,"abstract":"In Positron Emission Tomography (PET) detectors based in monolithic scintillators, the spatial resolution is limited by the accuracy in the determination of the interaction coordinates from the 511 keV photons. When linear algorithms, such as Center of Gravity (CoG) are used a poor estimation of the interaction positions, specially towards the edges is the major limitation in spatial resolution. A novel PET detector block, where complete information of Light Distribution (LD) for each event is available, allows to fit each event to a theoretical model, improving the estimation of the interaction coordinates, and minimizing border effects. In this work, by means of the LD fitting approach, we were able to obtain an average spatial resolution of 1.2 mm in the entire scintillator volume and an average depth of interaction (DOI) resolution of 1.5 mm. Moreover, splitting the data in three DOI regions, we obtained an average spatial resolution of 1.0 mm at the DOI region closer to the photodetectors. Finally, it is remarkable that the implementation of the LD fitting approach is capable of processing up to 50 kcps in a octacore system.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124697807","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: 8

Multidimensional characterization of cadmium-zinc-telluride coplanar-grid detectors 碲化镉锌共面栅格探测器的多维表征

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7431276

R. Michiels, C. Disch, U. Parzefall, A. Fauler, M. Fiederle

引用次数: 0

A Disc-DIRC Cherenkov detector with high resolution micro channel plate photomultiplier tubes 具有高分辨率微通道板光电倍增管的Disc-DIRC切伦科夫探测器

2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) Pub Date : 2014-11-01 DOI: 10.1109/NSSMIC.2014.7431161

J. Rieke, M. Duren, E. Etzelmuller, K. Fohl, A. Hayrapetyan, B. Krock, O. Merle, R. Dzhygadlo, A. Gerhardt, K. Gotzen, G. Kalicy, M. Krebs, H. Kumawat, D. Lehmann, M. Patsyuk, K. Peters, G. Schepers, L. Schmitt, C. Schwarz, J. Schwiening, M. Traxler, M. Zuhlsdorf, V. Dodokhov, F. Uhlig, A. Britting, W. Eyrich, A. Lehmann, E. Cowie, T. Keri, R. Montgomery, P. Achenbach, M. Cardinali, M. Hoek, W. Lauth, S. Schlimme, C. Sfienti, M. Thiel, P. Buhler, L. Gruber, J. Marton, K. Suzuki

{"title":"A Disc-DIRC Cherenkov detector with high resolution micro channel plate photomultiplier tubes","authors":"J. Rieke, M. Duren, E. Etzelmuller, K. Fohl, A. Hayrapetyan, B. Krock, O. Merle, R. Dzhygadlo, A. Gerhardt, K. Gotzen, G. Kalicy, M. Krebs, H. Kumawat, D. Lehmann, M. Patsyuk, K. Peters, G. Schepers, L. Schmitt, C. Schwarz, J. Schwiening, M. Traxler, M. Zuhlsdorf, V. Dodokhov, F. Uhlig, A. Britting, W. Eyrich, A. Lehmann, E. Cowie, T. Keri, R. Montgomery, P. Achenbach, M. Cardinali, M. Hoek, W. Lauth, S. Schlimme, C. Sfienti, M. Thiel, P. Buhler, L. Gruber, J. Marton, K. Suzuki","doi":"10.1109/NSSMIC.2014.7431161","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431161","url":null,"abstract":"The upcoming PANDA Experiment at FAIR in Germany will be equipped with a novel Cherenkov detector type for high-energy particle identification. This very compact Disc-DIRC detector uses a large disc-shaped fused silica plate of 2 cm thickness as its Cherenkov radiator. The internally reflected Cherenkov light is transported to the rim of the disc where it is focused by quartz light guides onto microchannel plate photomultiplier tubes (MCP-PMTs) with high spatial resolution (pitch 0.5 mm) and high time resolution (σ ≈ 100 ps). The device has an active area of about 3 m2 and will be able to identify pions and kaons with a separation power of more than 3σ in the momentum range up to 4 GeV/c. It has 32400 individual pixels and each can handle a mean photon rate of up to about 100 kHz. The presented design deals with numerous challenges that come with the very hostile environment in which the detector has to function properly, caused by the presence of high magnetic fields of up to 2 Tesla, high levels of radiation, high particle and background rates and a tight spatial volume. First test measurements have shown the performance of the design.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124788296","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