地球同步轨道卫星在轨异常与空间环境相关性分析

利用中国FY和美国GOES卫星探测数据,对中国某同步轨道卫星发生在2010年至2015年的44次可能与空间环境相关的异常进行了研究,重点分析了异常发生的时间分布、伴随的空间环境现象和空间粒子分布特征,并利用DICTAT模拟计算了卫星异常期间介质内部最大电场强度,结果表明:(1)内部充电是造成"3·17"卫星异常的主要原因。(2)79.5%卫星异常发生在日侧,这与能量2Me V的高能电子通量随地方时分布非常一致。(3)多达25次(57%)的异常事件伴随高能电子暴。能量2Me V电子通量的50%位数在异常前3-4天开始出现明显增强,内部充电危险商数ZIC在异常前2天进入黄色风险等级;能量2Me V电子通量的75%位数在异常前4天开始出现明显增强,ZIC在异常前2天先后2次进入红色风险等级。(4)在II类、III类和IV类情形下,DICTAT模拟计算得到的介质内部最大电场分别在19.2、50.4和9.8小时之后超过并维持在106V.m-1以上,该范围的内部电场强度存在潜在的放电危险,高能电子诱发的内部充电是造成我国同步轨道卫星异常的主要原因。     

适用于微纳卫星的微型电离层光学探测器

文章介绍了质量小、体积小的微型电离层光学探测器技术,给出了探测器的探测原理和设计方案,通过探测原子氧远紫外夜气辉(136.5 nm)辐射强度,反演电离层总电子含量(TEC)。采用轻量化铝反射镜、抗干扰电荷前放设计,实现反射镜、工业级远紫外探测器、电子学的一体化和小型化,研制出适用于微纳卫星的1 kg量级微型空间电离层光学探测器。该型探测器能够利用微纳星群多种轨道搭载,可获得丰富数据的优势,获取全球电离层高时空分辨率总电子含量分布,为未来实现卫星编队探测提供载荷研制基础。     

暗物质粒子空间间接探测

空间间接探测是暗物质探测的重要手段。我国暗物质粒子探测卫星"悟空号"通过测量电子能谱结构、伽马射线谱线等对暗物质进行间接探测。为了满足空间实验要求,精确测量电子、核素及伽马射线的能谱结构,暗物质粒子探测卫星采用4个子探测器,从上到下分别是塑料闪烁体阵列探测器、硅微条径迹探测器、锗酸铋晶体量能器和中子探测器。它们协同工作,保证了探测效率、本底抑制能力和粒子分辨力。卫星各性能参数符合设计要求,部分指标处于世界同类探测器先进水平。根据运行前530天的数据,得到了能量高达5 TeV的电子能谱精细结构,并首次在空间发现了电子能谱在0.9 TeV的拐折行为。     

一种基于石墨烯的脉冲星导航X射线探测器

针对脉冲星导航要求X射线探测器具有高能量分辨率和高时间分辨率的需求,研究基于石墨烯电场效应来实现X射线探测的可行性。通过蒙特卡罗方法模拟不同能量X射线和不同厚度探测器基底的相互作用过程,得到不同厚度探测器对X射线的探测效率。利用有限元方法分析X射线在探测器内电离产生载流子的输运过程,验证了X射线入射对石墨烯电学特性的影响。理论分析计算探测器的时间分辨率和能量分辨率等指标参数,结果表明：基于石墨烯电场效应的X射线探测器具有较高的能量分辨率和时间分辨率,是一种潜力巨大的X射线探测方式,可满足未来脉冲星导航的工程应用。     

航天器对空间带电粒子方向探测的需求分析

空间高能粒子很强的各向异性分布,对三轴稳定卫星各个方向的影响带来巨大的差异。通过探测高能带电粒子的方向分布及能谱测量,为卫星设计制造、在轨管理和故障分析提供最有效、最直接的保障。本文还简单介绍了我国新一代空间环境探测仪器——空间粒子方向探测器。该仪器集成了高能电子、质子的多方向通量测量和精细能谱测量,首次实现了180。粒子方向测量。     

基于BG算法的微波成像仪图像重建技术研究

基于用FY-3气象卫星微波成像仪(MWRI)的有效视场(EFOV),用BG算法对MWRI的空间分辨率重构进行了研究。给出了重建原理,引入折中参数控制分辨率与噪声的比例。对MERI的10.65GHz V通道进行了分辨率重构,在有效扫描角±45°区域内使用重构采样算法,确定重采样分辨率60km、折中参数为1×10-6,并获得了此条件下各探测通道最优重构分辨率及重构后的性能指标。结果表明:MWRI统一探测分辨率60km时,18.7,23.8,36.5,89GHz通道的噪声被大幅抑制,合成足迹的噪声为原始噪声的约10%,插值误差均小于5%,MWRI所有通道可很好地工作于匹配分辨率60km。     

萤火一号火星探测器电子分析器设计和试验

对萤火一号(YH-1)火星探测器电子分析器设计和试验进行了研究.电子分析器采用带偏转板的同轴圆柱形静电分析器,设计方案在满足性能指标的同时实现了小型化.用Ni63放射源对其进行能量扫描、角度扫描、能量和角度均扫描等能量高端的性能试验,结果表明:电子分析器的能量扫描、角度扫描、能量和角度均扫描功能正确.通过试验还获得了电子分析器在2.47～10.04 keV的相对探测效率,该结果可作为电子分析器在轨数据处理的依据.     

一种2π视场高分辨热等离子体分析仪设计与仿真

针对空间热等离子探测中大通量动态范围、宽视场和高分辨率的需求，以带顶盖球形静电分析器为基础设计了2π视场热等离子体分析仪(Hot plasma analyzer, HPA)，探测性能得到显著提升。通过优化球形剖面视场偏转系统以及粒子光学系统，实现对热等离子体的2π视场高角度分辨率探测，可探测能量范围覆盖50 eV~20 keV，能量分辨率优于10%。利用顶盖电压控制方式实现几何因子在两个量级内连续可调，可以满足对太阳风和磁层热等离子体的全空间高分辨探测需求。     

行星际粒子统计特征及其在深空探测用 器件失效概率预估中的应用

文章针对深空探测任务高能粒子辐射及所致器件失效定量评估问题,利用IMP-8在1973年—2001年的电子探测数据,统计了太阳电子事件通量的特征,证明事件通量符合对数正态分布。假设事件发生概率符合泊松分布,构建了行星际电子通量模型,再结合太阳质子通量模型、探测器轨道、行星际粒子在日球层的传播规律,得到不同置信度下空间粒子通量及其剂量。进一步结合器件累计失效剂量的试验数据,可定量评估器件失效概率。以一种典型的商用数据采集功能模块器件TL084和火星环绕探测任务为例,7个月转移轨道和3年火星轨道的任务期内,1 mm铝屏蔽下TL084的失效概率仅为1.01%。     

空间电子辐照下星用热缩套管力学性能退化试验研究

为掌握星用热缩套管的力学性能在空间带电粒子辐射环境中的退化情况,分别利用1 Me V高能电子和45 ke V低能电子模拟地球同步轨道带电粒子辐射环境,研究热缩套管在这2种不同能量电子辐照下断裂伸长率和抗拉强度性能退化情况。试验结果表明,辐照后热缩套管颜色由透明变为黄色,力学性能均出现显著退化现象,且高能电子辐照后退化较低能电子辐照后更为严重。文章通过能量沉积分析、辐解气体分析、表面形貌分析和X射线光电子能谱分析等多种手段,对试验结果做出了合理解释。本研究对开展结构材料力学性能退化地面模拟试验中的能量粒子选择有指导意义。     

Evaluation of the spectrometric and dose characteristics of neutron fields inside the Russian segment of the ISS by fission detectors

The results of measuring the dose and the energy spectrum of neutrons inside the Russian segment of the International Space Station (ISS) from March 21 until November 10, 2002 are presented. Statistically reliable results of measurement are obtained by using thorium- and uranium-based fission detectors with cadmium and boron filters. The kits of the detectors with filters have been arranged in three compartments within assembled passive detectors in the BRADOS space experiment. The ambient dose rate H* = 139 μSv day and an energy spectrum of neutrons in the range of 10^–2–10⁴ MeV is obtained as average for the ISS compartments and is compared with the measurements carried out inside the compartments of the MIR space station. Recommendations on how to improve the procedure for using the fission detectors to measure the characteristics of neutron fields inside the compartments of space stations are formulated.     

Energetic particle measurements onboard Spectr-R with MEP-2

The energetic particle experiment MEP-2 onboard the Spectr-R high apogee satellite is briefly described. The instrument measures fluxes and spectra of electrons (30 keV–350 keV) and ions (30 keV–3.2MeV), using two pairs of silicon detectors. The example of first observations upstream from the bow shock illustrates its successful operation in space. Unique observations of ～30 s strong fluctuations of energetic ions with energies up to two hundred keV are discussed.     

航天器防护高能带电粒子的新方法

文章介绍了航天器防护高能带电粒子的一种新方法——利用磁鞘进行主动防护。阐述了磁鞘防护高能带电粒子的基本原理,分析了其在工程应用上的可行性,并提出了磁鞘的一种设计方案。针对这种设计方案进行了数值分析计算,结果表明该方案可以有效防护0.15MeV以下的电子。     

空间相机低频隔振系统及试验验证

随着遥感卫星分辨率的提高。星上微振动对空间相机的影响越来越显著。在相机与卫星平台之间安装隔振装置,将飞轮、扫描机构等扰振源产生的振动与相机隔离开来是一种改善其工作环境的有效方法。文章介绍了针对中巴地球资源卫星研制的相机被动隔振系统,以及在地面结构星上进行的联合隔振性能测试。测试结果表明。传递至相机的两个主要扰振频率分量...     

Analysis of the pre-flight and post-flight calibration procedures performed on the Liulin space radiation dosimeter

Liulin, a dosimetry-radiometry system, was developed to satisfy the requirements for active flux and dose rate measurements for the flight of the second Bulgarian cosmonaut in 1988. The system consists of a compact battery-operated silicon solid state detector unit and a read/write microcomputer and telemetry unit. We describe the pre-flight calibrations with charged particles, using radioactive sources and accelerated 170 MeV/nucleon proton and alpha particles at the Dubna, Russia cyclotron. We discuss comparisons with data obtained on Mir with the French-built tissue equivalent LET spectrometer NAUSICAA. Lastly, we describe post-flight calibrations performed with 1 GeV/nucleon 56Fe ions at the Brookhaven National Laboratory AGS accelerator, where the instrument was mounted in tandem with several thin position-sensitive silicon detectors behind a stopping target. The silicon detectors provided an energy spectrum for the surviving charged nuclear fragments for which the flux and absorbed dose were recorded by Liulin.     

Short increases of the fluxes of electrons with energies > 0.08 MeV at low-latitude (<Emphasis Type="Italic">L</Emphasis> < 2) regions of near-Earth space

We present the characteristics of short (duration less than 1 min) increases of the counting rate of electrons with energies >0.08 MeV observed in low-latitude (L < 2.0) regions of near-Earth space in the course of the GRIF experiment on the Spektr module of the Mir orbital station. The measurements were carried out using a set of instruments including X-ray and gamma-ray spectrometers, as well as detectors of electrons, protons, and nuclei with large and small geometrical factors, which allowed one to detect the fluxes of charged particles both in the region of the Earth’s radiation belts and in regions close to the geomagnetic equator. As a result of more than 1.5 years of observation, it is demonstrated that short increases in the intensity of electrons of subrelativistic energies are detected not only in the regions of the near-Earth space known as “precipitation zones” (1.7 < L < 2.5), but in high-latitude regions (up to the geomagnetic equator, L < 1.1) as well. Two types of increases of the electron counting rate are found: either fairly regular increases repeating on successive orbits or increases local in time. The latter type of increases can be caused by a short enhancement of electron flux on a given drift shell. The results of our measurements have shown that the duration of the detected increases in intensity can be rather short, as little as 20–30 s. Therefore, in the case of large amplitudes, such increases of the counting rate of electrons can imitate astrophysical events of the type of cosmic gamma-ray bursts in the detectors of hard X-ray and gamma radiation.     

Probabilistic assessment of radiation risk for astronauts in space missions

Accurate estimations of the health risks to astronauts due to space radiation exposure are necessary for future lunar and Mars missions. Space radiation consists of solar particle events (SPEs), comprised largely of medium energy protons (less than several hundred MeV); and galactic cosmic rays (GCR), which include high-energy protons and heavy ions. While the frequency distribution of SPEs depends strongly upon the phase within the solar activity cycle, the individual SPE occurrences themselves are random in nature. A solar modulation model has been developed for the temporal characterization of the GCR environment, which is represented by the deceleration potential, ?. The risk of radiation exposure to astronauts as well as to hardware from SPEs during extra-vehicular activities (EVAs) or in lightly shielded vehicles is a major concern for radiation protection. To support the probabilistic risk assessment for EVAs, which could be up to 15% of crew time² on lunar missions, we estimated the probability of SPE occurrence as a function of solar cycle phase using a non-homogeneous Poisson model [1] to fit the historical database of measurements of protons with energy>30 MeV, Φ₃₀. The resultant organ doses and dose equivalents, as well as effective whole body doses, for acute and cancer risk estimations are analyzed for a conceptual habitat module and for a lunar rover during space missions of defined durations. This probabilistic approach to radiation risk assessment from SPE and GCR is in support of mission design and operational planning for future manned space exploration missions.     

火箭弹初始扰动实验研究

利用"光学杠杆"原理研制了火箭弹初始扰动激光测量系统。介绍了该系统的基本原理和构成,系统中所用半导体激光发射器激光波长650 nm,位置灵敏探测器(PSD)的分辨率为10-6m,角度测量误差小于2×10-5rad。利用该系统对54 mm火箭弹进行了实际测试,对实验结果与理论计算结果进行了对比,证明实验结果合理可信。最后对测量系统进行了误差分析。