用于空间辐射环境探测的金刚石探测器研究综述

空间辐射环境探测可减轻或避免辐射环境对航天器和宇航员的危害,已成为近年来各航天大国研究空间环境的热点。对空间辐射环境进行探测的探测器较多,包括气体探测器、闪烁体探测器和半导体探测器,半导体探测器具有能量分辨率高、探测效率高等优点,已逐渐取代其他两种探测器。金刚石辐射探测器是半导体探测器的一种,具有探测精度高、耐候性好、无需制冷、寿命长以及抗辐射能力强等优点,特别适合长周期、强辐射的深空探测。同时,金刚石禁带宽度大,不响应可见光,可实现日盲观测,已被欧洲空间局(ESA)用于太阳紫外辐射探测。俄罗斯工业技术中心在多种粒子复合探测方面正在研制宇宙射线光谱仪,尽管探测能区集中在中高能,但该光谱仪可实现电子、质子和重粒子的复合探测。基于目前金刚石辐射探测器在单粒子辐射探测中的应用及空间复杂的多种粒子辐射环境,我国的空间辐射环境探测研究应通过设计基于多层金刚石膜的单粒子辐射探测器来提高探测器的能量分辨率,再构建探测器矩阵进行多种粒子复合探测,将人工神经网络算法引入数据处理过程,以拓展探测范围到低能区,实现全能量范围粒子的探测,从而为开展金刚石探测器在空间站、深空辐射环境探测等领域的应用探索奠定基础。     

CVD金刚石膜紫外光探测器

宽禁带半导体金刚石具有许多独特特性，基于此种材料的紫外光探测器能在高温、强腐蚀和强辐射等恶劣环境下工作，成为近年来紫外探测技术研究的重点课题之一。本文综述了CVD金刚石膜紫外光探测器的研究及应用进展。     

CVD金刚石紫外探测器

CVD金刚石紫外探测器有极强的辐射硬度及耐腐蚀性,在宽禁带半导体紫外探测器中占有重要地位.本文主要对金刚石紫外探测器的发展进展、探测机理、电极模式及应用领域做了简要回顾.     

空间尘埃探测方案研究

空间环境中飞行的尘埃粒子会对进行深空探测的航天器有重大影响,它们会撞击并沉积在航天器表面结构中,影响航天器的性能。利用空间尘埃探测器可以探测尘埃的质量、速度、飞行方向、通量、化学成分及其元素同位素、所带电荷等参数。空间尘埃探测器的基本结构设计,用软件仿真计算了撞击离子在反射式质谱计反射腔内的轨迹,验证了其探测空间尘埃的化学成分的可行性。随着深空探测的逐步深入,空间尘埃探测器探测数据将成为航天器维护及未来空间科学研究的重要参考。     

基于(100)定向金刚石薄膜的辐射探测器研究

采用微波等离子体化学气相沉积（MPCVD）方法制备了100μm米厚高质量(100)定向金刚石薄膜. 利用(100)定向金刚石薄膜成功制备了α粒子探测器, -100V偏压下电荷平均收集效率为37.7%, 最大的电荷收集效率达到60%以上. 在此基础上, 通过在α粒子探测器条状电极面蒸镀一层合适厚度的硼(10B)膜转化层, 成功研制了金刚石中子探测器. 镀硼之后探测器对中子有明显的响应, 在1V/μm电场下, 对252Cf中子的能量分辨率达到9.3%,探测效率达到1.67%. 同时还研究了电场强度和硼(10B)层厚度对器件探测效率的影响规律. 在厚度<1.5μm时, 随着厚度的增加, 探测效率上升, 当厚度>1.5μm时, 探测效率下降.     

空间外差光谱技术实验研究

空间外差光谱技术是一种可实现超光谱分辨率的新型光谱分析技术,该技术综合光栅与FTS技术于一体.介绍了空间外差光谱仪基本原理以及系统光学结构,并对其性能进行了分析讨论.以实验室搭台的方式建立了空间外差光谱仪原理试验装置;经检测,装置在591nm波段的光谱分辨能力达17700,光谱范围为17nm.在原理试验装置上进行了激光、连续光谱、Hg双线和Na双线光源的空间外差光谱实验.实验结果显示了空间外差光谱技术在超高光谱分辨率探测的能力.     

金刚石膜辐射探测器的研究进展

阐述了金刚石作为激发材料在辐射探测器中的应用范围,比较了硅、化学气相沉积(CVD)金刚石膜和天然金刚石作为探测器用激发材料的性能优劣,介绍了CVD金刚石膜辐射探测器的原理和结构,综述了金刚石辐射探测器的国内外研究进展,展望了CVD金刚石膜辐射探测器的应用前景.     

半导体探测器在诊断X射线剂量测量中的应用

介绍了基于半导体探测器的诊断X射线剂量仪的工作原理.半导体探测器具有体积小、易于集成、灵敏度高、能量分辨率好等特点,根据半导体探测器的特征设计了能谱测量剂量修正功能,解决了半导体探测器能量响应差的问题.将能谱测量后修正过的剂量与未进行剂量修正的测量数据进行了比较,实验数据表明,能谱法修正将基于半导体探测器的剂量仪的能量响应降低至5%内.     

深空电推进阻滞势分析仪探测方法研究

随着人类对外太空环境认识的不断深入,电推进已成为通向未知空间领域的重要技术途径。空间电推进对航天器防护结构、能源系统、敏感有效载荷系统均产生不同影响。介绍了基于阻滞势分析仪的电推进等离子体参数探测方法,通过阻滞势分析仪研制和相应的地面模拟实验,计算得到了推力器40cm处的粒子能量、离子密度和离子温度等参数,相关研究为我国电推进航天器的深空应用和发展提供技术参考。     

宽能平面型HPGe探测器能量刻度及MC模拟

为更好服务于环境辐射监测,通过标准放射点源241Am、133Ba、60Co、137Cs、152Eu对平面型HPGe探测器进行标定,分别获得不同特征能量下的探测效率、半高宽、道址等数据。数据处理后得到能量-道址函数、FWHM能量刻度函数、能量与探测效率关系,同时求得能量分辨率为1.58keV(60Co,1.33MeV)。通过对比发现,利用CT技术建立的MC模型更加可靠、高效。通过修正上、下死层厚度依次分段对模型探测效率进行校正,得到整体探测效率相对误差在5%以内,与实验结果符合较好。     

High resolution detection of x-rays with a Nb-based STJ detector

A high energy-resolution of 88 eV has been achieved for 5.9-keV x-rays with a large area (178×178 µm²) Nb/Al-AlOx/Al/Nb superconducting tunnel junction (STJ) detector, which is stable at room temperature and robust to thermal cycles. The energy resolution is higher than those of semiconductor detectors. The resolution and the short shaping-time-constant, 2 µs, of the main amplifier used to obtain the energy resolution indicate that STJ detectors can be developed as nuclear radiation detectors with high energy resolution even for high rate radiations. Besides, a theoretical limit of energy resolution due to the statistical fluctuation of signal charges is discussed.     

Principles of Highly Resolved Determination of Texture and Microstructure using High‐Energy Synchrotron Radiation

Diffraction imaging with hard X‐rays (high‐energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation‐ and location‐resolution. These techniques provide continuous two‐dimensional images of different sections and projections of the six‐dimensional “orientation‐location” space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 10⁵ individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams corresponds to a pole density as a function of the orientation‐location space.     

A large high-resolution sodium iodide spectrometer

The new NaI detector system for high-energy gamma-ray detection at The Svedberg Laboratory is presented together with results from test experiments. The system has high efficiency, good energy resolution and rejects cosmic radiation efficiently. For example, the resolution is 1.6% at 22.6 MeV, the best value obtained so far for a NaI detector in this size category.     

Large diameter radial semiconductor drift chambers for low noise radiation detection

A semiconductor drift chamber with cylindrical symmetry has been investigated theoretically for its suitability as a low noise radiation detector. The signal/noise of a silicon drift chamber at room temperature is likely to be determined by the detector dark current and the drift chamber should be superior in performance to a conventional pn junction detector of equivalent dimensions. A device of 48 mm diameter and 300 μm thickness is predicted to be capable of an energy resolution of less than 5 keV fwhm at 300 K. This is about seven times better than that predicted for its conventional counterpart.     

Development of cryogenic alpha spectrometers using metallic magnetic calorimeters

Cryogenic particle detectors have recently been adopted in radiation detection and measurement because of their high energy resolution. Many of these detectors have demonstrated energy resolutions better than the theoretical limit of semiconductor detectors. We report the development of a micro-fabricated magnetic calorimeter coupled to a large-area particle absorber. It is based on a planar, 1 mm² large paramagnetic temperature sensor made of sputtered Au:Er, which covers a superconducting meander-shaped pickup coil coupled to a low-noise dc-SQUID to monitor the magnetization of the sensor. A piece of gold foil of 2.5×2.5×0.07 mm³ was glued to the Au:Er film to serve as an absorber for incident alpha particles. The detector performance was investigated with an ²⁴¹Am source. The signal size comparison for alpha and gamma peaks with a large difference in energy demonstrated that the detector had good linear behavior. An energy resolution of 2.83±0.05 keV in FWHM was obtained for 5.5 MeV alpha particles.     

The xenon olive detector for the next generation colliders

We propose a fast detector with high resolution and fine granularity, consisting of a xenon electromagnetic shower counter and a TMS-uranium hadron calorimeter. Both are linear in energy, insensitive to radiation damage and have good spatial resolution in 3-dimensional space in order to measure di-electron and di-jet masses at the next generation high luminosity colliders.     

On the possibility of eliminating the energy threshold for electron detection in semiconductor detectors

A method of eliminating the energy threshold for electron detection in semiconductor devices is described. The class of devices used for the detection and measurement of electron emission is sufficiently large, including electrostatic analyzers, gas-filled devices, microchannel plates, etc. An alternative to these types of devices for electron detection is offered by semiconductor radiation detectors based on the p-n junctions, which are widely used in the spectrometry of nuclear particles including medium-and high-energy electrons (10² keV and above). These detectors are obviously advantageous in comparison to the devices of other types, but there are several factors hindering the use of semiconductor detectors for the detection and analysis of low-energy electrons (in the kiloelectronvolt range). We propose an approach that allows the energy threshold for electron detection in semiconductor detectors to be eliminated by means of preliminary acceleration of the detected particles in an electrostatic field created between the emitter and the detector. This approach removes the basic factor limiting the use of semiconductor detectors in a number of diagnostic methods based on the analysis of electron emission, such as the extended X-ray absorption fine structure (EXAFS), surface EXAFS, and X-ray absorption near-edge structure (XANES) techniques.     

使用单能X射线辐射装置对CdTe探测效率的实验刻度

CdTe探测器对单能平行光子源的绝对测量之前,需要进行效率刻度。利用MCNP5蒙特卡罗模拟程序建立CdTe探测器物理模型,模拟计算了10~260keV能量段能点的本征探测效率,在10~60keV能量段探测效率高于75%。用单能X射线装置和HPGe探测器对CdTe探测器本征探测效率进行了实验刻度。结果表明,在10~100keV能量范围内CdTe探测器的模拟效率与实验效率趋势一致,最大误差不超过5.6%。因为Te元素在27keV和32keV处会产生逃逸峰,导致探测效率在这2个能量处有明显下降趋势。用241Am和133Ba放射源对CdTe探测器进行效率刻度验证,在能量为59.54keV和81keV放射源标定的探测效率与单能X射线辐射装置测量值相符。     

Development and application of CVD diamond detectors to 14 MeV neutron flux monitoring

CVD diamond is an interesting material for radiation detection, its atomic number (Z = 6) is close to that of soft tissues (Z = 7.1) and it can also work in harsh environments. Since many years CVD diamond films have been grown at the Faculty of Engineering, Rome 'Tor Vergata' University, and in 1998 a collaboration with ENEA Fusion Division was established to develop fast neutron monitors to be used in fusion tokamak environment. In this paper the first test of a 120 microm thick polycrystalline CVD diamond detector used for monitoring 14.7 MeV neutrons emission produced with the Frascati Neutron Generator (FNG) is reported. The detector operates in air and in pulse mode. The time irradiation profiles recorded with the CVD diamond detector were compared with those recorded by the standard monitors available at FNG (SSD, fission chamber, NE-213). Good stability and capability to operate in neutron flux up to 1.5 x 10(8) n cm(-2) s(-1) was observed. The radiation hardness property was also investigated using a 460 microm thick film and these results are also reported.