空间电子、质子和紫外综合辐照模拟试验研究

文章介绍了地面模拟地球同步轨道15年电子、质子和紫外环境的综合辐照模拟试验技术,为长寿命卫星热设计及热控涂层选型提供可靠依据。试验采用空间低能综合环境试验设备、太阳吸收率原位测试系统,针对卫星各种表面材料如S781白漆、SR107-ZK白漆、F46镀银和OSR二次表面镜等进行了空间低能综合辐照试验,与已有的飞行试验数据进行对比研究,结果表明：本次试验能够较准确地反映航天器在轨道上材料的退化现象。     

高精度航天器微振动力学环境分析

高精度航天器由于其指向精度和分辨率水平极高,需要考虑微振动的影响。文章给出了微振动的定义,分析了微振动特性、国外研究现状、建模特点及方法,总结归纳了高精度航天器星体内部的主要扰动源。给出了反作用轮、斯特林低温制冷器、星载敏感器以及太阳翼等典型扰动源扰动的时域或频域模型及微振动隔离模型,并进行了相应的仿真,从系统层面评估了微振动对高精度航天器性能的影响,可供高精度航天器设计时参考。     

航天器太阳电池阵分流技术研究

对航天器太阳电池阵分流技术进行了归纳总结,对PWM,S3R和S4R三种开关分流调节技术进行了详细的原理分析,比较总结各自的技术特点。并对S3R和S4R技术进行了深入研究,对S3R技术进行了详细的设计与计算,对S4R技术典型工况进行了详细分析与实验验证。同时对三种开关分流技术做出了评价。     

太阳辐射对ER3BP拉格朗日点的影响

为了研究Halo轨道中继通信以及行星际轨道转移等问题,需要首先对拉格朗日点(平动点)的理论进行分析。使用考虑太阳辐射的椭圆型限制性三体建模,代替原有的圆型限制性三体建模,提高了建模的精度。提出了在L1,L2,L3点的更为精确的新解析解,经过Matlab仿真,其相对于精确数值解的误差,分别为Ammar的解析解的13.13%,29.51%,0.46%。     

On the early phase of relativistic solar particle events: Are there signatures of acceleration mechanism?

Many physical processes precede and accompany the solar energetic particles (SEP) occurrence on the Earth’s orbit. Explosive energy release on the Sun gives rise to a flare and a coronal mass ejection (CME). X-ray and gamma emissions are believed to be connected with flares. Radio emission is signature of disturbances traveling through the corona and interplanetary space. Particles can gain energy both in the flare and the accompanying wave processes. The beginning of the SEP events has the advantage of being the phase most close to the time of acceleration. Influence of interplanetary transport is minimal in the case of first arriving relativistic solar protons recorded by ground based neutron monitors in so called ground-level enhancements (GLE). The early phase of the SEP events attracts attention of many scientists searching for the understanding of particle acceleration. However, they come to the opposite conclusions. While some authors find arguments for coronal mass ejections as a sole accelerator of SEPs, others prove a flare to be the SEP origin. Here, the circumstances of SEP generation for several GLEs of the 23rd solar cycle are considered. Timing of X-ray, CME, and radio emissions shows a great variety from event to event. However, the time of particle ejection from the Sun is closer to maximum of X-ray emission than to any other phenomena considered. No correlation is found between the particle fluxes and the CME characteristics.     

High energy charged particle experiment – A payload proposal to KuaFu-B mission

High Energy Charged Particle Experiment (HECPE) is to measure the fluxes of MeV electrons and tens of MeV protons. The two satellites of KuaFu-B are in the same polar orbit with apogee 7.0R_E, perigee 1.8R_E. They can sweep large L values and pass through the inner and outer radiation belts. The high energy electrons and protons in the radiation belts are principal sources for failures of satellites and spacecrafts in the Earth orbits. The enhancements of the high energy electrons and protons, so-called energetic particle events, are important phenomena of the Space Weather. The energy ranges monitored by HECPE are 0.3–0.5 MeV, 0.5–1.0 MeV, 1.0–2.0 MeV, and E > 2.0 MeV for electrons, 5–10 MeV, 10–20 MeV, 20–40 MeV, and 40–80 MeV for protons.     

Ion and electron superdiffusive transport in the interplanetary space

We study the propagation of energetic particles, accelerated by interplanetary shock waves, upstream of the shock. By using the appropriate propagator, we show that in the case of superdiffusive transport, the time profile of particles accelerated at a traveling planar shock is a power-law with slope 0<γ<1$0<\gamma <1$, at variance with the exponential profile obtained for normal diffusion. By analyzing data sets of interplanetary shocks in the solar wind observed by the Ulysses and the Voyager 2 spacecraft, we find that the time profiles of energetic electrons correspond to power-laws, with slopes γ?0.30–0.98$\gamma ?0.30''–''0.98$, implying a mean square displacement 〈Δx²〉∝t^α$〈\mathrm{\Delta }{x}^2〉\propto t^{\alpha }$, with α=2-γ>1$\alpha =2-\gamma >1$, i.e., superdiffusion. In addition, the propagation of ions is also superdiffusive, with α=1.07–1.13$\alpha =1.07''–''1.13$.     

Observations of Irradiance Variations

Since November 1978 a complete set of total solar irradiance (TSI) measurements from space is available, yielding a time series of 21 years. From measurements made by different space radiometers (HF on NIMBUS-7, ACRIM I on SMM, ACRIM II on UARS and VIRGO on SOHO) a composite record of TSI can be compiled. The corrections which are needed for each radiometer, mainly to compensate for degradation, but also for operational influences are described. ACRIM I (1980–1989) and ACRIM II (1992–1995) are taken as reference because their degradation was monitored by inflight comparisons with spare radiometers; since 1996 VIRGO is used as reference. The scale of ACRIM II is adjusted to ACRIM I by comparison with NIMBUS-7 and ERBE. The reliability of this adjustment depends strongly on the stability of the HF and ERBE radiometer during the period of the gap between the ACRIMs which is discussed in detail together with an assessment of the overall precision of the composite.     

空间发电系统热能储存容器的二维模型

高温熔盐相变储热是空间太阳能热动力发电系统的关键技术之一。基于微重力状态下的传热控制微分方程, 采用焓法对相变材料容器进行了二维数值分析。建立了一种新的空穴模型, 改进了以往的模拟计算, 对计算结果给予了讨论。      

回旋波共振加热加速的多重离子流体模型

在回旋波共振准线性理论基础上建立了自恰描述质子和氧离子各向异性温度和整体速度的双离子流体模型,求得数值解,并与UVCS观测相比较.发现在波谱斜率固定的假设下,模型的数值结果虽然与观测有相同趋势,但不能在误差范围之内解释全部观测现象.进一步的研究需要考虑波谱形状的自洽演化.