In the research and development of new silicon pixel detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pixel-beam telescope is crucial for prototype verification and perfo...In the research and development of new silicon pixel detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pixel-beam telescope is crucial for prototype verification and performance evaluation.When the beam energy is low,the effect of multiple Coulomb scattering on the measured resolution of the Device Under Test(DUT)must be considered to accurately evaluate the performance of the pixel chips and detectors.This study aimed to investigate the effect of multiple Coulomb scattering on the measured resolution,particularly at low beam energies.Simulations were conducted using Allpix^(2) to study the effects of multiple Coulomb scattering under different beam energies,material budgets,and telescope layouts.The simulations also provided the minimum energy at which the effect of multiple Coulomb scattering could be ignored.Compared with the results of a five-layer detector system tested with an electron beam at DESY,the simulation results were consistent with the beam test results,confirming the reliability of the simulations.展开更多
Background Shanghai HIgh repetition rate XFEL aNd Extreme light facility(SHINE)is a free electron laser facility,which will provide research methods such as high-resolution imaging for many disciplines.The pixel detec...Background Shanghai HIgh repetition rate XFEL aNd Extreme light facility(SHINE)is a free electron laser facility,which will provide research methods such as high-resolution imaging for many disciplines.The pixel detector,which is in the pre-research stage,is one of most important components of the facility.Purpose The current target data rate of the pixel detector in SHINE is about 100 GB/s.Considering the high data rate,the 10G/40G Ethernet firmware for pixel detector in SHINE was developed on field programmable gate array(FPGA),which will lead to more integrated electronic design and make the system smaller.Methods The firmware converts the media independent interfaces(MII)of 10G and 40G Ethernet to each other and uses a polling method to process data from four 10G Ethernet channels.Based on the above methods,the firmware can merge four 10G Ethernet channels into one 40G Ethernet channel.Results and Conclusion The firmware successfully transmits data between the data source and the server.The bandwidth of the firmware is 36.66 Gbps when the computer equipped with 10G network interface controller(NIC)is set as the data source.Through joint test with the 1G/10G hub and SiTCP,the bandwidth of firmware is 36.3 Gbps.And 40 SiTCP nodes whose system clock frequency can exceed 125 MHz can be used as the data source of the firmware,which will provide a variety of technical solutions for pixel detector.展开更多
A silicon pixel detector with fine pitch size of 19 μm × 19 μm, developed based on SOI （silicon-on- insulator） technology, was tested under the illumination of infrared laser pulses. As an alternative method ...A silicon pixel detector with fine pitch size of 19 μm × 19 μm, developed based on SOI （silicon-on- insulator） technology, was tested under the illumination of infrared laser pulses. As an alternative method for particle beam tests, the laser pulses were tuned to very short duration and small transverse profile to sinmlate the tracks of MIPs （minimum ionization particles） in silicon. Hit cluster sizes were measured with focused laser pulses propagating through the SOI detector perpendicular to its surface and most of the induced charge was found to be collected inside the seed pixel. For the first time, the signal amplitude as a function of the applied bias voltage was measured for this SOI detector, deepening understanding of its depletion characteristics.展开更多
Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The...Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The detector consists of CMOS pixel sensors at wafer scale using chip stitching technology.The chips are thinned to a flexible thickness of about 50μm.PMI foams are used as spacers and auxiliary support between the adjacent layers,enabling the first layer of the detector to be put as close to the central beam pipe as possible.The detector structure has been optimized through finite-element analysis(FEA).Result The material budget of the detector has been reduced to about 0.077%Xo per layer.The maximum deformation of the chip edge has been controlled to±80μm after bending,and the roundness is about 100μm,which verifies the feasibility of the cylindrical detector prototype structure.In addition,the wire bonding process for the cylindrical silicon pixel detector has been tested and preliminarily validated.Conclusion This study validates the process flow for the development of large-area cylindrical detectors based on stitching technology,laying a foundation for the smooth progress of subsequent study.展开更多
After approximately half a century of development, HgCdTe infrared detectors have become the first choice for high performance infrared detectors, which are widely used in various industry sectors, including military ...After approximately half a century of development, HgCdTe infrared detectors have become the first choice for high performance infrared detectors, which are widely used in various industry sectors, including military tracking, military reconnaissance, infrared guidance, infrared warning, weather forecasting, and resource detection. Further development in infrared applications requires future HgCdTe infrared detectors to exhibit features such as larger focal plane array format and thus higher imaging resolution. An effective approach to develop HgCdTe infrared detectors with a larger array format size is to develop the small pixel technology. In this article, we present a review on the developmental history and current status of small pixel technology for HgCdTe infrared detectors, as well as the main challenges and potential solutions in developing this technology. It is predicted that the pixel size of long-wave HgCdTe infrared detectors can be reduced to5 μm, while that of mid-wave HgCdTe infrared detectors can be reduced to 3 μm. Although significant progress has been made in this area, the development of small pixel technology for HgCdTe infrared detectors still faces significant challenges such as flip-chip bonding, interconnection, and charge processing capacity of readout circuits. Various approaches have been proposed to address these challenges, including three-dimensional stacking integration and readout circuits based on microelectromechanical systems.展开更多
This study presents an electronics system for cosmic X-ray polarization detection(CXPD).The CXPD was designed as a high-sensitivity soft X-ray polarimeter with a measurement energy range of 2-10 keV carried by a CubeS...This study presents an electronics system for cosmic X-ray polarization detection(CXPD).The CXPD was designed as a high-sensitivity soft X-ray polarimeter with a measurement energy range of 2-10 keV carried by a CubeSat.A stable and functionally complete electronics system under power and space constraints is a key challenge.The complete CXPD electronics system(CXPDES)comprises hardware and firmware.CXPDES adopts a three-layer electronic board structure based on functionality and available space.Two gas pixel detectors(GPDs)were placed on the top layer board,and CXPDES provided the GPDs with voltages up to-4000 V.Each GPD signal was digitized,compressed,encoded,and stored before being transmitted to the ground.The CXPDES provided stable and high-speed communication based on a scheme that separated command and data transmission,and it supports the CXPDES in-orbit upgrade.In addition,environmental monitors,silicon photomultiplier(SiPM)triggers,power management,GPDs configuration,and mode switches were included in the overall operating logic of the CXPDES.The results obtained by testing the CXPDES showed that it satisfied all the requirements of CXPD.The CXPDES provides design experience and technological readiness for future large-area X-ray polarimetry missions.展开更多
Carbon ions,commonly referred to as particle therapy,have become increasingly popular in the last decade.Accurately predicting the range of ions in tissues is important for the precise delivery of doses in heavy-ion r...Carbon ions,commonly referred to as particle therapy,have become increasingly popular in the last decade.Accurately predicting the range of ions in tissues is important for the precise delivery of doses in heavy-ion radiotherapy.Range uncertainty is currently the largest contributor to dose uncertainty in normal tissues,leading to the use of safety margins in treatment planning.One potential method is the direct relative stopping measurement(RSP)with ions.Heavy-ion CT(Hi′CT),a compact segmented full digital tomography detector using monolithic active pixel sensors,was designed and evaluated using a 430 MeV/u high-energy carbon ion pencil beam in Geant4.The precise position of the individual carbon ion track can be recorded and reconstructed using a 30μm×30μm small pixel pitch size.Two types of customized image reconstruction algorithms were developed,and their performances were evaluated using three different modules of CAT-PHAN 600-series phantoms.The RSP measurement accuracy of the tracking algorithm for different types of materials in the CTP404 module was less than 1%.In terms of spatial resolution,the tracking algorithm could achieve a 20%modulation transfer function normalization value of CTP528 imaging results at 5 lp/cm,which is significantly better than that of the fast imaging algorithm(3 lp/cm).The density resolution obtained using the tracking algorithm of the customized CTP515 was approximately 10.5%.In conclusion,a compact digital Hi'CT system was designed,and its nominal performance was evaluated in a simulation.The RSP resolution and image quality provide potential feasibility for scanning most parts of an adult body or pediatric patient,particularly for head and neck tumor treatment.展开更多
面向高能同步辐射光源(High Energy Photon Source,HEPS)的高性能像素阵列探测器(HEPS-BPIX4)的数据获取系统(Data Acquisition,DAQ)需满足高实时性要求。通过在线压缩图像数据,可有效降低后续传输与存储的压力。针对传统压缩算法在压...面向高能同步辐射光源(High Energy Photon Source,HEPS)的高性能像素阵列探测器(HEPS-BPIX4)的数据获取系统(Data Acquisition,DAQ)需满足高实时性要求。通过在线压缩图像数据,可有效降低后续传输与存储的压力。针对传统压缩算法在压缩率和实时性方面的不足,本文提出了一种基于深度学习目标检测的图像数据在线压缩方法。采用端到端的YOLO(You Only Look Once)目标检测算法,对深度学习模型进行高效训练,并验证了其在HEPS-BPIX4 DAQ数据流中实现在线数据压缩的可行性。实验结果表明,该方法的图像数据在线压缩平均压缩比达到5.88。同时,设计了高效的部署方案,并对性能进行了测试,单线程下的压缩处理速率可达GB∙s^(−1)量级。此外,进一步提出了适用于HEPS-BPIX4 DAQ框架的多线程部署方案,以满足更高的压缩性能需求,为缓解HEPS-BPIX4 DAQ系统高带宽图像数据处理压力提供了新思路。展开更多
介绍了多波段红外探测器的应用开发进展,并且针对多波段信号同时探测的红外器件特点进行了读出电路设计。其中,Pixel输入级为多波段红外探测器读出电路设计的核心关键模块之一。本文设计采用了缓冲直接注入型(Buffered Direct Injection...介绍了多波段红外探测器的应用开发进展,并且针对多波段信号同时探测的红外器件特点进行了读出电路设计。其中,Pixel输入级为多波段红外探测器读出电路设计的核心关键模块之一。本文设计采用了缓冲直接注入型(Buffered Direct Injection,BDI)像素输入级电路结构,具有高稳定性、低等效输入阻抗的特点,有效提高长波器件的注入效率,并且为光电探测器件提供了稳定的工作条件。以CMOS 0.18μm 5 V标准工艺基础,完成了全电路设计与模拟仿真。结果表明:70 K低温下电路功能正常,40μm间距内含有短、中、长4波段像素输入级,输入级积分信号输出线性度达到99.7%,噪声不超过0.3 mV。展开更多
本文采用CdZnTe单晶制成像素探测器,并对其能谱响应特性及均匀性进行了系统表征。通过I-V和能谱响应测试,测定了晶体的电阻率和载流子迁移率与寿命的积,并用红外透过显微成像观察了晶体内Te夹杂的分布特性。采用光刻、剥离和真空蒸镀技...本文采用CdZnTe单晶制成像素探测器,并对其能谱响应特性及均匀性进行了系统表征。通过I-V和能谱响应测试,测定了晶体的电阻率和载流子迁移率与寿命的积,并用红外透过显微成像观察了晶体内Te夹杂的分布特性。采用光刻、剥离和真空蒸镀技术,在CdZnTe晶片上制备了8×8的像素电极,用丝网印刷和贴片技术通过导电银胶实现像素电极与读出电路的准确连接,制备出CdZnTe像素探测器。对像素探测器的测试表明,-300V下单像素最大漏电流小于0.7nA,对241 Am 59.5keV的能量分辨率可达5.6%,优于平面探测器。进一步分析了晶体内Te夹杂等缺陷对探测器漏电流和能谱响应特性的影响规律,结果表明,Te夹杂的聚集会显著增加漏电流,并降低探测器的能量分辨率。展开更多
基金supported by the National Natural Science Foundation of China(Nos.11875274 and U1232202)。
文摘In the research and development of new silicon pixel detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pixel-beam telescope is crucial for prototype verification and performance evaluation.When the beam energy is low,the effect of multiple Coulomb scattering on the measured resolution of the Device Under Test(DUT)must be considered to accurately evaluate the performance of the pixel chips and detectors.This study aimed to investigate the effect of multiple Coulomb scattering on the measured resolution,particularly at low beam energies.Simulations were conducted using Allpix^(2) to study the effects of multiple Coulomb scattering under different beam energies,material budgets,and telescope layouts.The simulations also provided the minimum energy at which the effect of multiple Coulomb scattering could be ignored.Compared with the results of a five-layer detector system tested with an electron beam at DESY,the simulation results were consistent with the beam test results,confirming the reliability of the simulations.
基金This work was supported by Xie Jialin Fund,Insti-tute of High Energy Physics,Chinese Academy of Sciences.
文摘Background Shanghai HIgh repetition rate XFEL aNd Extreme light facility(SHINE)is a free electron laser facility,which will provide research methods such as high-resolution imaging for many disciplines.The pixel detector,which is in the pre-research stage,is one of most important components of the facility.Purpose The current target data rate of the pixel detector in SHINE is about 100 GB/s.Considering the high data rate,the 10G/40G Ethernet firmware for pixel detector in SHINE was developed on field programmable gate array(FPGA),which will lead to more integrated electronic design and make the system smaller.Methods The firmware converts the media independent interfaces(MII)of 10G and 40G Ethernet to each other and uses a polling method to process data from four 10G Ethernet channels.Based on the above methods,the firmware can merge four 10G Ethernet channels into one 40G Ethernet channel.Results and Conclusion The firmware successfully transmits data between the data source and the server.The bandwidth of the firmware is 36.66 Gbps when the computer equipped with 10G network interface controller(NIC)is set as the data source.Through joint test with the 1G/10G hub and SiTCP,the bandwidth of firmware is 36.3 Gbps.And 40 SiTCP nodes whose system clock frequency can exceed 125 MHz can be used as the data source of the firmware,which will provide a variety of technical solutions for pixel detector.
基金Supported by National Natural Science Foundation of China(11375226)
文摘A silicon pixel detector with fine pitch size of 19 μm × 19 μm, developed based on SOI （silicon-on- insulator） technology, was tested under the illumination of infrared laser pulses. As an alternative method for particle beam tests, the laser pulses were tuned to very short duration and small transverse profile to sinmlate the tracks of MIPs （minimum ionization particles） in silicon. Hit cluster sizes were measured with focused laser pulses propagating through the SOI detector perpendicular to its surface and most of the induced charge was found to be collected inside the seed pixel. For the first time, the signal amplitude as a function of the applied bias voltage was measured for this SOI detector, deepening understanding of its depletion characteristics.
基金supported by the National Natural Science Foundation of China(No.U2032203).
文摘Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The detector consists of CMOS pixel sensors at wafer scale using chip stitching technology.The chips are thinned to a flexible thickness of about 50μm.PMI foams are used as spacers and auxiliary support between the adjacent layers,enabling the first layer of the detector to be put as close to the central beam pipe as possible.The detector structure has been optimized through finite-element analysis(FEA).Result The material budget of the detector has been reduced to about 0.077%Xo per layer.The maximum deformation of the chip edge has been controlled to±80μm after bending,and the roundness is about 100μm,which verifies the feasibility of the cylindrical detector prototype structure.In addition,the wire bonding process for the cylindrical silicon pixel detector has been tested and preliminarily validated.Conclusion This study validates the process flow for the development of large-area cylindrical detectors based on stitching technology,laying a foundation for the smooth progress of subsequent study.
文摘After approximately half a century of development, HgCdTe infrared detectors have become the first choice for high performance infrared detectors, which are widely used in various industry sectors, including military tracking, military reconnaissance, infrared guidance, infrared warning, weather forecasting, and resource detection. Further development in infrared applications requires future HgCdTe infrared detectors to exhibit features such as larger focal plane array format and thus higher imaging resolution. An effective approach to develop HgCdTe infrared detectors with a larger array format size is to develop the small pixel technology. In this article, we present a review on the developmental history and current status of small pixel technology for HgCdTe infrared detectors, as well as the main challenges and potential solutions in developing this technology. It is predicted that the pixel size of long-wave HgCdTe infrared detectors can be reduced to5 μm, while that of mid-wave HgCdTe infrared detectors can be reduced to 3 μm. Although significant progress has been made in this area, the development of small pixel technology for HgCdTe infrared detectors still faces significant challenges such as flip-chip bonding, interconnection, and charge processing capacity of readout circuits. Various approaches have been proposed to address these challenges, including three-dimensional stacking integration and readout circuits based on microelectromechanical systems.
基金supported by the National Natural Science Foundation of China (Nos.11875146,U1932143)National Key Research and Development Program of China (No.2020YFE0202002)。
文摘This study presents an electronics system for cosmic X-ray polarization detection(CXPD).The CXPD was designed as a high-sensitivity soft X-ray polarimeter with a measurement energy range of 2-10 keV carried by a CubeSat.A stable and functionally complete electronics system under power and space constraints is a key challenge.The complete CXPD electronics system(CXPDES)comprises hardware and firmware.CXPDES adopts a three-layer electronic board structure based on functionality and available space.Two gas pixel detectors(GPDs)were placed on the top layer board,and CXPDES provided the GPDs with voltages up to-4000 V.Each GPD signal was digitized,compressed,encoded,and stored before being transmitted to the ground.The CXPDES provided stable and high-speed communication based on a scheme that separated command and data transmission,and it supports the CXPDES in-orbit upgrade.In addition,environmental monitors,silicon photomultiplier(SiPM)triggers,power management,GPDs configuration,and mode switches were included in the overall operating logic of the CXPDES.The results obtained by testing the CXPDES showed that it satisfied all the requirements of CXPD.The CXPDES provides design experience and technological readiness for future large-area X-ray polarimetry missions.
基金the National Natural Science Foundation of China(Nos.11975292,12205374,U2032209,and 12222512)Beijing Hope Run Special Fund of Cancer Foundation of China(No.LC2021B23)+1 种基金the CAS“Light of West China”Program,the CAS Pioneer Hundred Talent Program,the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)the National Key Research and Development Program of China(No.2021YFA1601300 and 2020YFE0202002).
文摘Carbon ions,commonly referred to as particle therapy,have become increasingly popular in the last decade.Accurately predicting the range of ions in tissues is important for the precise delivery of doses in heavy-ion radiotherapy.Range uncertainty is currently the largest contributor to dose uncertainty in normal tissues,leading to the use of safety margins in treatment planning.One potential method is the direct relative stopping measurement(RSP)with ions.Heavy-ion CT(Hi′CT),a compact segmented full digital tomography detector using monolithic active pixel sensors,was designed and evaluated using a 430 MeV/u high-energy carbon ion pencil beam in Geant4.The precise position of the individual carbon ion track can be recorded and reconstructed using a 30μm×30μm small pixel pitch size.Two types of customized image reconstruction algorithms were developed,and their performances were evaluated using three different modules of CAT-PHAN 600-series phantoms.The RSP measurement accuracy of the tracking algorithm for different types of materials in the CTP404 module was less than 1%.In terms of spatial resolution,the tracking algorithm could achieve a 20%modulation transfer function normalization value of CTP528 imaging results at 5 lp/cm,which is significantly better than that of the fast imaging algorithm(3 lp/cm).The density resolution obtained using the tracking algorithm of the customized CTP515 was approximately 10.5%.In conclusion,a compact digital Hi'CT system was designed,and its nominal performance was evaluated in a simulation.The RSP resolution and image quality provide potential feasibility for scanning most parts of an adult body or pediatric patient,particularly for head and neck tumor treatment.
文摘本文采用CdZnTe单晶制成像素探测器,并对其能谱响应特性及均匀性进行了系统表征。通过I-V和能谱响应测试,测定了晶体的电阻率和载流子迁移率与寿命的积,并用红外透过显微成像观察了晶体内Te夹杂的分布特性。采用光刻、剥离和真空蒸镀技术,在CdZnTe晶片上制备了8×8的像素电极,用丝网印刷和贴片技术通过导电银胶实现像素电极与读出电路的准确连接,制备出CdZnTe像素探测器。对像素探测器的测试表明,-300V下单像素最大漏电流小于0.7nA,对241 Am 59.5keV的能量分辨率可达5.6%,优于平面探测器。进一步分析了晶体内Te夹杂等缺陷对探测器漏电流和能谱响应特性的影响规律,结果表明,Te夹杂的聚集会显著增加漏电流,并降低探测器的能量分辨率。
