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中能电子测量对空间辐射环境的理论研究和空间航天器的防护设计具有重要意义。北京大学研制的中能电子成像谱仪(BD-IES)利用小孔成像技术实现多方向中能电子的能谱测量。地面标定试验结果表明,BD-IES具有良好的能量线性度和较小的系统噪声,能够有效实现对中能电子的能谱测量。该仪器已成功应用在我国导航卫星上。最新测量结果表明BD-IES对中能电子的测量是成功的,其结果对于研究如亚暴注入、波-粒子相互作用等空间物理热点问题具有重要意义。BD-IES未来将被应用到"风云"等空间环境探测平台上。 相似文献
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通过仿真计算南大西洋异常区(SAA)高能粒子的通量与能量,分析不同通量阈值与能量阈值对SAA空间分布的影响,并以科学实验卫星为研究对象,对其历经SAA的时间百分比进行连续24 h和6个月的统计,获得了SAA对卫星常规运行的工作时间影响。结果表明:在50 MeV能量阈值条件下,500 cm~(-2)?s~(-1)较100 cm~(-2)?s~(-1)通量阈值对SAA空间分布的影响范围在纬度上相差约23.35%,经度上相差约27.06%,历经SAA时间上缩短约48.0%;在100 cm~(-2)?s~(-1)通量阈值条件下,150 MeV较50 MeV能量阈值对SAA空间分布的影响范围在纬度上相差约13.86%,经度上相差约17.29%,历经SAA时间上缩短约31.7%。 相似文献
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为研究大椭圆轨道(HEO)航天器介质深层充电规律特征,基于FLUMIC模型建立辐射带电子环境模式,初步分析了诱发HEO深层充电的高能电子环境,计算了介质材料在HEO环境下的充电特征,并与地球同步轨道(GEO)下的情况进行对比。结果表明,HEO电子平均积分通量与GEO的相比处于同一量级,但存在明显波动,这将导致卫星在轨运行时,其上介质平均充电电位上升,增加内带电的风险。HEO介质平均充电电位为GEO的1.3倍,瞬时电位以12 h周期波动,电位最大值较环境电子通量最大值有数十min延时。增加屏蔽层厚度和减小介质厚度均能有效减缓HEO卫星介质电位波动,并降低内带电的风险。 相似文献
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合成了2,6-二氨基-3,5-二硝基吡啶-1-氧化物(ANPyO) Bi(III)含能配合物,采用FTIR、元素分析和XPS光电子能谱表征了含能配合物的结构.根据结构表征结果推测,ANPyO Bi(III)含能配合物的分子式为Bi(C5H4N5O5)3,金属离子与配体的配比为1∶3.其中,可能的配位方式为:每个配体ANPyO 2-位的氨基脱去一个氢原子,分别以NH和N→O结构单元中N原子和O原子与Bi(III)形成配位键.ANPyO Bi(III)含能配合物的撞击感度、摩擦感度和冲击波感分别为220 cm、36 kg和5.8 mm.采用TG-DTG和DSC测试考察了ANPyO Bi(III)含能配合物的热分解行为,配合物在50~450 ℃范围内热分解过程由一个吸热熔融峰和分解放热峰组成,相应的峰温分别为320.6 ℃和346.5 ℃,配合物热分解剩余残渣量为31.2%.同时,考察了配合物对高氯酸铵热分解的催化作用,并采用Kissinger法对纯AP和AP混合物热分解过程低温分解阶段和高温分解阶段的表观活化能和指前因子进行了计算.结果表明,ANPyO Bi(III)含能配合物可使高氯酸铵高温分解阶段和低温分解阶段的峰温提前63.6 ℃和63.1 ℃,表观活化能降低23.1 kJ/mol和61.5 kJ/mol,表观分解热增加339.3 J/g.可发现,ANPyO Bi(III)含能配合物对AP的热分解具有显著的催化作用. 相似文献
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高能电子辐照下聚合物介质深层放电实验研究 总被引:2,自引:1,他引:1
为揭示聚合物介质材料在连续能谱高能电子辐射下的深层放电规律特征,利用~(90)Sr放射源对聚四氟乙烯(PTFE)材料进行了不同条件的辐照实验。对采集的大量放电数据进行统计分析发现,电子辐照累积时间、入射电子通量以及温度都会影响介质的放电风险以及放电脉冲特征。高能电子对样品持续数天的累积辐照会降低介质自发放电的阈值条件,辐照后期放电更加频繁,但放电强度会减弱。入射电子通量越低时,放电风险越小;通量越高时,放电频率越高,高强度放电事件的发生概率也越大。温度主要通过影响介质的电导率而影响其深层放电特性,温度下降时介质本征电导率降低,充电电位和放电风险增加;一旦发生放电,放电电流脉冲的平均幅度也更大。 相似文献
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C. Plainaki H. Mavromichalaki A. Belov E. Eroshenko V. Yanke 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
In order to understand the physics under extreme solar conditions such as those producing ground level enhancements of solar cosmic rays, it is important to use accurate and reliable models. The NM-BANGLE Model is a new cosmic ray model which couples primary solar cosmic rays at the top of the Earth’s atmosphere with the secondary ones detected at ground level by neutron monitors during GLEs. This model calculates the evolution of several GLE parameters such as the solar cosmic ray spectrum, anisotropy and particle flux distribution, revealing crucial information on the energetic particle propagation and distribution. The total output of the NM-BANGLE Model is a multi-dimensional GLE picture that gives an important contribution to revealing the characteristics of solar energetic particle events recorded at ground level. In this work, the results of the NM-BANGLE Model application to the recent GLE of 13 December 2006 are presented and discussed. Moreover, a comparison with the extreme event of 20 January 2005 (GLE69) has been realized. 相似文献
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A.L. Mishev P.I.Y. Velinov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(1):316-325
The influence of high energy particles, specifically cosmic rays, on atmospheric physics and chemistry is highly discussed. In most of the proposed models the role of ionization in the atmosphere due to cosmic rays is not negligible. Moreover, effect(s) on minor constituents and aerosols are recently observed, specifically over the polar regions during strong solar particle events. According to the recent findings for such effects it is necessary an essential increase of ion production, specifically during the winter period. The galactic cosmic rays are the main source of ionization in the Earth’s stratosphere and troposphere. Occasionally, the atmospheric ionization is significantly enhanced during strong solar energetic particles events, specifically over the polar caps. During the solar cycle 23 several strong ground level enhancements were observed. One of the strongest was the Bastille day event occurred on 14 July 2000. Using a full Monte Carlo 3-D model, we compute the atmospheric ionization, considering explicitly the contribution of cosmic rays with galactic and solar origin, focusing on high energy particles. The model is based on atmospheric cascade simulation with the PLANETOCOSMICS code. The ion production rate is computed as a function of the altitude above the sea level. The ion production rate is computed on a step ranging from 10 to 30?min throughout the event, considering explicitly the spectral and angular characteristics of the high energy part of solar protons as well as their time evolution. The corresponding event averaged ionization effect relative to the average due to galactic cosmic rays is computed in lower stratosphere and upper troposphere at various altitudes, namely 20?km, 15?km, 12?km and 8?km above the sea level in a sub-polar and polar regions. The 24h and the weekly ionization effects are also computed in the troposphere and low stratosphere. Several applications are discussed. 相似文献