硅(锂)X射线探测器

介绍了10～80mm~2的硅(锂)X射线探测器研制工艺,并讨论了工艺过程和测量中的一些问题;给出了探测器的指标,这些指标大都达到和接近国外同类产品水平。硅(锂)X射线探测器是一种低能X射线探测器,它具有能量分辨率高、线性好,对低能区X射线探测效率高等特点,在核物理、医学、地矿、环保等领域有着广泛的应用。它也是扫描电镜,X射线荧光分析等能谱分析的核心部件。     

一种可测低能γ和X射线的高纯n型硅探测器

采用蒸发金、钯和离子注入硼作势垒接触,低温扩散锂制备欧姆接触的方法,制成性能良好的低能γ和X射线高纯硅探测器。介绍其制作方法和性能。探测器有效面积为14.5mm~2,厚度3.3mm。在液氮温度下对~(55)Fe 5.9kev X射线的最佳能量分辨率为162eV,对~(241)Am59.5keV低能γ射线的最佳能量分辨率为373eV。同时对三种不同制作方法所得的高纯硅探测器和Si(Li)X射线探测器进行了对比。     

高阻NTD硅低能β,γ和X射线探测器

本文叙述了高阻NTD硅低能β,γ和X射线探测器的制备工艺和性能,探测器的灵敏面积为15mm~2,厚2.3mm。在77K温度下用脉冲光反馈前置放大器对最大端点能量为18.6keV的氚β,~(241)Am 59.5keV的低能γ和X射线的能谱及~(55)Fe 5.9keV的X射线进行了测量。对~(55)Fe 5.9keV的X射线能量分辨率为190eV,并可在室温下存放。     

硅(锂)X射线探测器

介绍了10～80mm’的硅(锂)X射线探测器研制工艺,并讨论了工艺过程和测量中的一些问题;给出了探测器的指标,这些指标大都达到和接近国外同类产品水平。硅(理)X射线探测器是一种低能X射线探测器,它具有能量分辨率高、线性好,对低能区X射线探测效率高等特点,在核物理、医学、地矿、环保等领域有着广泛的应用。它也是扫描电镜X射线荧光分析等能谱分析的核心部件。     

半导体望远镜β射线谱仪

本文介绍了由厚度为0.3mm、面积为200mm~2的Si(Au)ΔE探测器和厚度为15mm、面积为500mm~2的HPGe E探测器组成的一套半导体望远镜β射线谱仪。其对单能电子的能量分辨为20keV。β谱处理程序可以很方便地用来分析多分支β谱,包括探测器响应函数修正和端点能量及分支比的提取。实验提取的~(152)Eu、~(90)Y和~(56)Mn三个已知β发射体核的端点能量及分支比结果与文献值符合得较好。HPGe探测器也可作为低能γ射线探测器。     

用于X射线探测的CVD金刚石薄膜探测器

研制了用于X射线测量的化学气相沉积(CVD)金刚石薄膜探测器.该探测器灵敏区直径为15 mm、厚度300 μm,其暗电流在800 V偏压下小于50 pA,且暗电流-电压曲线线性较好.就CVD金刚石探测器对不同能量X射线的响应及脉冲X射线时间响应进行了理论和实验研究.结果表明:该探测器对6～22 keV X射线具有10-4～10-2A·W-1的灵敏度,假设电荷收集效率为39%时,灵敏度的理论值与实验测量值符合较好,探测器的RC时间常数约为1.5 ns;对亚纳秒脉冲X射线的响应上升时间为2～3 ns.     

一个二维位置灵敏X射线探测器的研制

本文报道-个二维位置灵敏X射线探测器的研制.探测器采用多丝正比室(MWPC)结构,有效面积200×200mm2,采用阴极感应读出,由电荷重心法确定入射X射线位置.经测试,探测器的位置分辨(fwhm)好于0.4mm.     

CdTe探测器对EAST托卡马克中20–200keV硬X射线测量

介绍了EAST托卡马克装置硬X射线诊断系统。该系统由探测器阵列和电子线路组成,探测器采用水平七道的碲化镉(CdTe)探测器阵列。在EAST托卡马克装置上建立了一套较完善的硬X射线能谱诊断系统,用来测量等离子体在硬X射线辐射能段(20–200 keV)的能谱。实验结果表明,该系统能满足测量相应能量范围的等离子体硬X射线轫致辐射要求。文中给出了碲化镉探测器的标定结果及典型的放电结果。     

室温X(γ)射线半导体探测器的最新发展

在X(γ)射线能谱仪和工业检测仪表中以及剂量仪器中都期待理想的室温X(γ)射线半导体探测器的产生。 1982年11月彭华寿同志在第一次全国核探测器学术会议上作的“低能核辐射探测器进展”一文中谈到,多年来室温化合物半导体探测器的发展一直得到人们的注意,十多年来,国外较集中的对CdTe和HgI_2两种材料进行了研究,并取得了很大的进展,但尚     

基于碘化铅X射线探测器的信号处理研究

采用闭管物理气相输运法制备出PbI_2晶体,研制了PbI_2X射线探测器,对探测器的I-t等特性进行了表征,并设计了基于PbI_2探测器的单通道信号处理电路,主要涵盖前端放大、中央控制处理以及显示报警等几个模块。重点分析了探测器经放大电路后,输出电压与X射线间的特性关系,并由此建立灰度矩阵模型。实验结果表明,PbI_2X射线探测器的线性响应良好,与X射线属于线性对应关系;灰度值与输出电压值也有良好的线性关系,从而证明了PbI_2探测器应用于辐射检测领域的可行性,并为PbI_2X射线探测器的数字化成像提供了有效的参考依据。     

A study of gas electron multiplier

A new kind of gas detector based on gas electron multiplier (GEM) is studied for X-ray imaging of high luminosity. A single-GEM device is designed to test the prnperty of GEM foil ,The effective gain and counting capability of a double-GEM detector are measured by an X-ray tube with Cu target. An initial X-ray imaging experiment is carried out using a triple-GEM detcctor and the position iesolution of less than 0.1mm is achieved. The 3D distribution of electrostatic field of GEM mesh is also presented.     

CdTe semiconductor X-ray imaging sensor and energy subtractionmethod using X-ray energy information

A multichannel X-ray imaging sensor using a CdTe compound semiconductor radiation detector was developed. Both the digital X-ray imaging and energy-information-generating analyzing method were studied. The X-ray imaging sensor consisted of 512-channel CdTe detector elements at a pitch of 0.2 mm. X-ray photons were directly detected using a photon-counting method and high- and low-energy images were obtained simultaneously. The specific resolution was obtained over 2.5 line pairs/mm in the channel direction and 1.6 line pairs/mm in the scanning direction with a scanning pitch of 0.2 mm. The energy subtraction method was found to be effective in distinguishing an object's component materials     

高分辨率X射线探测器读出电子学系统的研制及性能测试

本文针对光锥耦合X射线探测器低噪声的设计要求,研制了一套读出电子学系统,该系统包括模拟驱动电路、前端处理电路及基于现场可编程门阵列(FPGA)的数字信号处理电路。利用X射线成像平台,对研发的探测器进行了性能测试。探测器系统绝对增益为0.168 6DN/e-,线性工作范围为0~154μGy。制冷温度为-20℃时,暗电流噪声为0.037e-/(pixel·s),读出噪声为10.9e-。探测器的本征空间分辨率达16lp/mm。测试结果表明,研制的读出电子学系统能满足高分辨率X射线探测器对低噪声特性的需求。     

用于HL-2A装置的新型硬X射线探测器

介绍了一种应用于托卡马克等离子诊断领域的新型硬X射线探测器,该探测器主要由硅酸钇镥(Lutetium-yttrium Oxyorthosilicate,LYSO)闪烁体和硅光电倍增管(Silicon Photomultiplier,Si PM)组成。基于项目应用需求,对探测器的选型和基于粒子输运蒙特卡罗仿真软件GEANT4的探测器设计加以阐述,并搭建了前端的探测系统,在HL-2A托卡马克装置上进行了现场诊断实验。实现了硬X射线空间能谱和辐射强度分布的诊断测量。实验表明该探测器阵列具有10 ms的时间分辨率,同时具有结构紧凑、使用方便等特点,能够满足等离子体诊断中硬X射线动态能谱和强度分布测量的诊断需求。     

A high position resolution X-ray detector: an "Edge on" illuminated capillary plate combined with a gas amplification structure

We have developed and successfully tested a prototype of a new high position resolution hybrid X-ray detector. It contains a thin-wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber operating in various gas mixtures at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90/spl deg/. The detection efficiency, depending on the geometry, photon's energy, incident angle and the mode of operation was between 5-30% in single step mode and up to 50% in a multi-layered combination. Depending on the capillary's geometry, the position resolution achieved was between 50-250 /spl mu/m in digital form and was practically independent of the photon's energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm/sup 2/ and hydrogen treated capillaries-up to 10/sup 5/ Hz/mm/sup 2/. The developed detector has several important potential advantages over the exciting X-ray detectors and may open new possibilities for medical imaging, for example in mammography, portal imaging, radiography (including security devices), as well as many other applications.     

Elongate X-ray detectors for application in security inspectionsystems

We have developed, manufactured, and investigated a novel type of long X-ray detector up to 1000 mm long with two exit windows. The sensitive element of the detector is an elongated polished rectangular plate of inorganic scintillator. The detector is highly sensitive to X-rays in the energy region 50-250 keV. The factors influencing the sensitivity and longitudinal uniformity of the detector response have been considered     

Upgrading of X-ray CT technology for analyses of irradiated FBR MOX fuel

The X-ray CT technology previously developed by JAEA was upgraded. The shape of the X-ray source beam was changed from a circular shape to an elliptical one and the collimator slit width was decreased from 0.3 to 0.1 mm. The X-ray detector was improved by changing a CdWO₄ scintillator to a highly sensitive silicon semiconductor detector. The analysis code of X-ray CT image was revised with respect to the number of points by using two kinds of experimental results and taking into account the effects of crack existence and deviation of the central void position from the radial center of a fuel pellet. As a result, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assemblies. The error of the dimensional measurement was improved from ±0.1 to ±0.03 mm by upgrading the instrument and revising the analysis code of X-ray CT image. The discriminating accuracy of density difference could be increased, and the low density region (undisturbed region) and high density region (equi-axial and columnar regions) in the X-ray CT image on the cross section of irradiated fuel could be discriminated from each other. The reliability of fuel performance analysis improves because a large number of PIE data can be collected, compared with the conventional destructive PIE.     

The Characteristics of an Ultra-High Resolution Ge(Li) Spectrometer for Singles and Coincidence X-Ray and Gamma-Ray Studies

The use of an ultra-high resolution Ge(Li) photon spectrometer in low and high energy X-ray and gamma-ray measurements has been evaluated. Studies were made of the resolution, low energy cutoff, the full energy and K X-ray escape efficiencies, tha effective detector dead layer and the detector linearity. The detector was used simultaneously with a high resolution Si(Li) detector to measure fast coincidences between Ka1 , Ka2 and L X-rays, as well as coincidences between K, L conversion electrons and L X-rays. A detailed discussion is presented of the electronic problems associated with making these kind of measurements. Measurements were also made of X-ray beams produced by clinical X-ray machines at 40, 78 and 220 kV.     

A novel compact Tokamak Hard X-ray diagnostic detector

A compact X-ray detector based on the lutetium yttrium oxyorthosilicate scintillator(LYSO) and silicon photomultiplier(Si PM) has been designed and fabricated for the hard X-ray diagnosis on the HL_2A and HL_2M Tokamak devices. The LYSO scintillator and Si PM in small dimensions were combined in a heat shrink tube package, making the detector compact and integrative. The Monte Carlo particle transport simulation tool,Geant4, was utilized for the design of the detector for the hard X-ray from 10 keV to 200 keV and the best structure scheme was presented. Finally, the detector was used to measure the photon spectrum of a ~(137)Cs gamma source with a pre-amplifier and a multichannel amplitude analyzer. The measured spectrum is consistent with the theoretic spectrum, it has shown that the energy resolution of the detector is less than 14.8% at an energy of 662 keV.