典型结构的深层充放电规律及放电干扰影响研究

发布时间：2018-05-15 20:27

本文选题：高能电子 + 深层充放电　；参考：《中国科学院大学(中国科学院国家空间科学中心)》2017年博士论文

【摘要】：空间高能电子导致的深层充放电效应一直是运行于地球外辐射区域的航天器所面临的最大空间环境危害之一。目前,受限于多方面因素,深层充放电效应的现有研究积累仍不能很好地满足实际工程需求,在航天器发射入轨前对其深层充放电风险进行准确评估仍旧存在较大困难。随着航天任务对高可靠、长寿命要求的不断增强以及新材料、新器件在航天器上的应用,从工程需求出发持续深入开展深层充放电效应研究对保障我国航天器在轨可靠性具有十分重要的意义。本论文利用中科院空间中心自主研发的航天器充放电效应模拟装置以及充电效应仿真软件,通过综合运用地面模拟试验、一维和三维仿真计算并结合理论分析等手段,针对具有代表性的航天器部件构型,开展了空间连续能谱高能电子辐照下典型结构的深层充放电特性、影响不同结构深层充放电特性的关键内在因素和外部环境条件、典型结构深层放电脉冲的基本特征以及深层放电脉冲对典型航天器件的影响规律等基础问题的研究,主要的研究内容和研究成果如下:1)开展了典型结构的深层充放电特性研究。主要针对平板型介质以及介质-导体相邻结构,研究了影响其深层充放电效应的各主要内在因素。对于平板介质,材料电导率、厚度以及接地方式是最主要的内在影响因素,为有效减缓平板介质的深层充电效应,应尽量选用电导率高的材料,减小介质的厚度,并在条件允许下采用双面接地。对于介质-导体相邻结构,介质最高表面电位以及内部最大电场均与介质宽度和高度呈正相关。当介质与导体侧面存在微小间隙时,介质内最大电场显著增强,极易发生内部击穿,而间隙区域的电场也很容易超过击穿阈值,从而使介质-导体间发生放电。2)开展了影响深层充放电效应的外部环境条件研究。以典型的平板介质为对象,研究了电子辐照累积时间、电子通量、温度、真空度以及轨道变化等环境条件对深层充放电效应的影响。高能电子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且放电强度减弱。辐照电子通量越高时,放电风险越大、频率越高。温度降低时介质本征电导率减小,充电电位和放电风险随之增加。介质在高真空度下更容易被充上高电位,当受到某种瞬态气体释放的影响时很容易诱发介质表面放电。当介质遭受周期性改变的高能电子环境时,其充电状态的变化往往滞后于电子通量的变化。3)开展了深层放电脉冲特征研究。对深层充放电试验中的大量放电数据进行统计分析,结果表明,深层放电脉冲幅度整体上随着放电时间间隔的增加而增大,放电间隔越长,发生高强度放电事件的概率越大。高通量电子辐照时,或者介质处于低温时,介质发生深层放电的风险更高,且放电电流的平均幅度更大,离散性更强。深层放电电流脉冲信号在时域上常常为欠阻尼高频振荡信号,而在频域上存在明显的特征峰,其振荡特性主要与放电回路的阻抗特性有关,样品厚度、温度以及辐照源对放电电流脉冲的频谱分布影响不大,只是低频部分稍有差别。4)开展了深层放电脉冲对典型星用器件的干扰影响研究。选取一款航天常用的集成运放为研究对象,对其进行了放电干扰模拟试验。结果表明,在模拟的空间静电放电干扰下,运放输出管脚会产生异常瞬态脉冲,脉冲特征受器件工作模式、偏置条件、放电电压及干扰耦合途径的影响。电压比较器只出现单一极性的输出瞬态脉冲,电压跟随器与同相放大器对放电的响应类似,而反相放大器对放电的敏感度相对较低。器件输入端耦合进的超过运放带宽的高频干扰信号是放电导致运放异常瞬态脉冲输出的根本原因,输出脉冲幅度、持续时间与输入端干扰信号幅度及频率呈现正相关性。
[Abstract]:The deep charge discharge effect caused by space high energy electrons has always been one of the largest space environmental hazards facing the spacecraft operating in the outer earth radiation area. At present, the existing research on the deep charge and discharge effect is still unable to meet the actual requirement of the practical process limited by many factors. There are still great difficulties in accurate assessment of charge and discharge risk. With the high reliability of the space mission, the continuous enhancement of the long life requirements and the application of new materials, new devices on the spacecraft, it is very important to study the deep deep charge and discharge effects from the needs of the engineering to ensure the reliability of our spacecraft on orbit. In this paper, the space center of the CAS Space Center is used to simulate the spacecraft charging and discharging effect simulation device and the charging effect simulation software. By using the ground simulation test, one and three dimensional simulation calculation and the theoretical analysis, the space continuous energy spectrum high-energy electricity is carried out for the representative spaceflight components. The characteristics of the deep charge and discharge of typical structures under the irradiation of sub radiation, the key internal factors and external environment conditions affecting the deep charge and discharge characteristics of different structures, the basic characteristics of the deep discharge pulse in the typical structure and the influence of the deep discharge pulse on the typical space devices, and the main research content and research results As follows: 1) the study of the deep charge and discharge characteristics of the typical structure is carried out. The main internal factors affecting the deep charge and discharge effects are studied mainly for plate and dielectric conductor adjacent structures, which are the most important internal factors for the plate medium, material conductivity, thickness and grounding mode, in order to effectively slow down the plate. The deep charge effect of medium should be used as far as possible to select material with high conductivity, reduce the thickness of the medium, and adopt double side grounding under the condition of condition. For the adjacent structure of medium conductor, the maximum surface potential and the maximum electric field of the medium are positively related to the width and height of the medium. When there is a small gap between the medium and the side of the conductor, the medium has a small gap. The internal maximum electric field is greatly enhanced, and the internal breakdown is very easy to occur, and the electric field in the gap region is easily exceeded by the breakdown threshold, thus the discharge.2 between the medium conductors is produced. The external environment conditions that affect the deep charge and discharge effect are studied. The effect of environmental conditions, such as vacuum and orbital change, on the deep charge and discharge effect. The cumulative irradiation of high-energy electrons will reduce the threshold conditions of spontaneous discharge of the medium, the discharge more frequent and the discharge intensity in the later period of irradiation. The higher the radiation flux, the greater the risk of discharge, the higher the frequency, the intrinsic characteristic of the dielectric. The electric conductivity decreases and the charge potential and the discharge risk increase. The medium is more likely to be filled with high potential at high vacuum. When affected by some transient gas release, the dielectric surface discharge is easily induced. When the medium suffers from periodic change of the high energy electronic environment, the change of the charge state of the medium is often lagged behind the change of the electron flux. The characteristics of deep discharge pulse are studied. A large number of discharge data in the deep charge discharge test are statistically analyzed. The results show that the depth of the deep discharge pulse increases with the increase of the discharge time interval, the longer the discharge interval is, the greater the probability of high intensity discharge event is. High flux electron irradiation, or.3 When the mass is at low temperature, the risk of deep discharge in the medium is higher, and the average amplitude of discharge current is greater and the dispersion is stronger. The deep discharge current pulse signal is often under the damping high frequency oscillating signal in the time domain, and there is a distinct characteristic peak in the frequency domain. The oscillation specificity is mainly related to the impedance characteristics of the discharge circuit, and the sample thickness is thick. Degree, temperature and irradiation source have little influence on the spectrum distribution of discharge current pulse, only the low frequency part has a slight difference of.4). The influence of deep discharge pulse on the interference of typical satellite devices is carried out. Under the interference of space electrostatic discharge, an abnormal transient pulse will be produced by the amp output pin. The characteristics of the pulse are influenced by the device working mode, the bias condition, the discharge voltage and the interference coupling approach. The voltage comparator only has a single polarity output transient pulse, and the response of the voltage follower and the same phase amplifier to the discharge is similar, but the reverse phase amplifier is similar. The sensitivity of the discharge is relatively low. The high frequency interference signal, which is coupled by the input end of the device, is the fundamental reason for the abnormal transient pulse output caused by the discharge. The amplitude and duration of the output pulse are positively correlated with the amplitude and frequency of the input interference signal.

【学位授予单位】：中国科学院大学(中国科学院国家空间科学中心)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：V416.5;V520

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