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Effects of Martian crustal magnetic field on its ionosphere

Science china(Technological Sciences) 2010年第6期53卷 1717-1724页

作者： zou hong,chen hongfei,yu ning,shi weihong,yu xiangqian,zou jiqing & zhong weiying institute of space physics and applied technology,peking university,beijing 100871,china 1. institute of space physics and applied technology Peking University Beijing 100871 China

The effect of the Martian crustal magnetic field is one of the hot topics of the study of Martian *** studies on this topic are summarized in this *** data of the Martian ionosphere were resulted from radio occultation *** to the observations,the electron density scale height and the peak electron density of the Martian ionosphere are influenced by its crustal magnetic *** strong horizontal magnetic field prevents the vertical diffusion of the plasma and makes the electron density scale height in the topside ionosphere close to that in the photo equilibrium *** the cusp-like regions with strong vertical magnetic field,the enhanced vertical diffusion leads to a larger electron density scale height in the diffusion equilibrium *** observation of radio occultation experiment onboard Mars Global Surveyor (MGS) showed that the averaged peak electron density observed in the southern hemisphere with strong crustal magnetic field was slightly larger than that in the northern hemisphere with weak crustal magnetic *** Mars advanced radar for subsurface and ionosphere sounding (MARSIS) onboard Mars Express (MEX) was the first topside sounder to be used to observe Martian *** MARSIS results confirmed that the enhancement of the peak electron density occurred in cusp-like regions with open field lines,and the amount of the enhancement was much larger than that observed by the radio occultation *** are two possible mechanisms for the peak electron density enhancement in the cusp-like crustal magnetic field regions:One is the precipitation of the energetic particles and the other is the heating by the waves excited by plasma ***'s difficult to determine which one is the key mechanism for the peak electron density *** on these studies,several interesting problems on the Martian ionosphere and plasma environment are presented.

关键词： Mars exploration Martian crustal megnetic field Martian ionosphere energetic particles detection plasma wave detection

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Variations of the relativistic electron flux after a magnetospheric compression event

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Science china(Technological Sciences) 2017年第4期60卷 638-647页

作者： chen Zhe chen hongfei LI YiFan XIANG hongWen yu xiangqian shi weihong HAO ZhiHua zou hong zou jiqing zhong weiying institute of space physics and applied technology Peking University Beijing 100871 China School of Electronic and Information Engineering Beihang University Beijing 100191 China beijing institute of spacecraft System Engineering Beijing 100094 China

On January 21, 2015, a sharp increase of the solar wind dynamic pressure impacted the magnetosphere. The magnetopause moved inward to the region L< 8 without causing a geomagnetic storm. The flux of the relativistic e... 详细信息

On January 21, 2015, a sharp increase of the solar wind dynamic pressure impacted the magnetosphere. The magnetopause moved inward to the region Lchina-Brazil Earth Resource Satellites(CBERS-4). The flux remained low for approximately 11 d; it did not recover after a small magnetic storm on January 26 but after a small magnetic storm on February 2. The loss and recovery of the relativistic electrons during this event are investigated using the PRM data, medium-and high-energy electron observations of NOAA-15 and the Van Allen Probes, medium-energy electron observations of GOES-13, and wave observations of the Van Allen Probes. This study shows that the loss of energetic electrons in this event is related to magnetospheric compression. The chorus waves accelerate the medium-energy electrons, which causes the recovery of relativistic electrons. The Van Allen Probes detected strong chorus waves in the region L =3–6 from January 21 to February 2. However, the flux of medium-energy electrons was low in the region. This implies that the long-lasting lack of recovery of the relativistic electrons after this event is due to the lack of the medium-energy"seed" electrons. The medium-energy electrons in the outer radiation belt may be a clue to predict the recovery of relativistic electrons.

关键词： outer radiation belt high-energy electrons medium-energy electrons space environment

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Direct measurement of the linear energy transfer of ions in silicon for space application

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Science china(Technological Sciences) 2016年第1期59卷 128-134页

作者： chen hongfei yu xiangqian SHAO SiPei shi weihong CUI ZhanGuo XIANG hongWen HAO ZhiHua zou jiqing zhong weiying zou hong institute of space physics and applied technology School of Earth and Space SciencesPeking UniversityBeijing 100871China institute of Shandong Aerospace technology Yantai 264003China china Academy of space technology beijing 100094 China

The single event effect(SEE) is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures. The linear energy transfer(LET) of ions is commonly investigated in studies of SEE. The use of a thin detector is an economical way of directly measuring the LET in space. An LET telescope consists of a thin detector as the front detector(D1), along with a back detector that indicates whether D1 was penetrated. The particle radiation effect monitor(PREM) introduced in this paper is designed to categorize the LET into four bins of 0.2–0.4, 0.4–1.0, 1.0–2.0 and 2.0–20 Me V·cm^2/mg, and one integral bin of LET>20 Me V·cm^2/mg. After calibration with heavy ions and Geant4 analysis, the LET boundaries of the first four bins are determined to be 0.236, 0.479, 1.196, 2.254, and 17.551 Me V·cm^2/mg, whereas that of the integral bin is determined to be LET>14.790 Me V·cm^2/mg. The acceptances are calculated by Geant4 analysis as 0.452, 0.451, 0.476, 0.446, and 1.334, respectively. The LET accuracy is shown to depend on the thickness of D1; as D1 is made thinner, the accuracy of the measured values increases.

关键词： linear energy transfer measurement LET single event effect space radiation

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Imaging energetic electron spectrometer onboard a Chinese navigation satellite in the inclined GEO orbit

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Science china(Technological Sciences) 2018年第12期61卷 1845-1865页

作者： zou hong YE yuGuang ZONG QiuGang chen hongfei zou jiqing chen Jiang shi weihong yu xiangqian zhong weiying WANG YongFu ZHOU XuZhi HAO YiXin chen XingRan JIA Xianghong XU Feng SHAO SiPei WANG Bo HAO Xiaoyun ZHANG XiaoXin institute of space physics and applied technology Peking University Beijing 100871 China State Key Laboratory of space Medicine Fundamentals and Application Chinese Astronaut Research and Training Center Beijing 100094 China Shandong Aerospace Electro-technology Yantai 264000 China Key Laboratory of space Weather National Center for Space Weather Beijing 100081 China

The energetic electron measurement is one of the most important issues to understand dynamics in space physics and the applications for space weather. In this study, the principle and functional components of the imaging energetic electron spectrometer(IES) onboard a Chinese navigation satellite in the inclined GEO orbit(IGSO) was introduced. The IES instrument is developed by the team in peking university(BeiDa), thus it is named as BD-IES. Based on the pin-hole technique, the instrument can measure 50–600 keV electrons incident from 9 directions over a range of 180° in polar angle. With pulse height analysis(PHA), the spectrum can be determined for each direction. The energy and angular calibrations were performed, which show the good energy and angular characteristics of BD-IES. Monte Carlo simulations show that the anti-proton design of BDIES can effectively decrease the proton contamination on the electron measurements in the inclined GEO orbit. The primary results of BD-IES verify the successful design of this instrument.

关键词： imaging energetic electron spectrometer pin-hole imaging system IGSO satellite

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存储器空间单粒子翻转率预测

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空间科学学报 2019年第4期39卷 460-468页

作者：陈傲陈鸿飞向宏文于向前施伟红邵思霈邹鸿邹积清仲维英北京大学地球与空间科学学院空间物理与应用技术研究所北京100871 中国空间技术研究院总体部北京100094 中国空间技术研究院513所山东264670

根据SSO上两卫星搭载的三个PREM测得的空间中重离子LET谱,以及利用Weibull分布模型拟合出的不同器件的σ-LET曲线,对由空间中重离子引起的单粒子翻转的翻转率进行了预测估算.将预测值与实测值对比,分析了影响翻转率的因素.对于相同器件... 详细信息

根据SSO上两卫星搭载的三个PREM测得的空间中重离子LET谱,以及利用Weibull分布模型拟合出的不同器件的σ-LET曲线,对由空间中重离子引起的单粒子翻转的翻转率进行了预测估算.将预测值与实测值对比,分析了影响翻转率的因素.对于相同器件,翻转率与设备在卫星上的位置和朝向有关.位于卫星尾部面向后退(-x)方向的翻转率高于位于底部对地(+z)方向的器件翻转率;太阳活动水平高的时间段翻转率高于太阳活动水平低的时间段.探测器接收的重离子微分LET谱的强度和硬度决定了器件的单粒子翻转率.在高于翻转LET阈值时,LET谱的强度越高,其硬度和翻转率越大.不同器件的翻转率也不相同.

关键词：单粒子翻转率预测单粒子效应重离子LET谱

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