由高能电子引发的风云二号C星跳变事件概率分析

通过对地球同步轨道高能电子监测数据(来自GOES)与风云二号卫星跳变事件的对比分析发现, 跳变事件均发生在高能电子增强事件即所谓高能电子暴期间, 因此初步断定, 跳变事件与高能电子引起的卫星介质深层充放电事件有关. 通过对不同通量高能电子增强事件期间所发生的跳变事件发生率进行量化计算, 给出跳变事件发生概率的计算方法, 为卫星在轨运行管理及防护提供参考.      

The LET spectrum and its uncertainty during the CRRES mission.

We present Linear Energy Transfer (LET) spectra calculated for the 1990-1991 CRRES mission using the galactic cosmic ray (GCR) and solar energetic particle (SEP) models developed for the CRRES/SPACERAD program and presented by Chen, et al. 1992 at this conference. We discuss how the spectra vary with changes in the galactic cosmic ray and solar energetic particle models. Finally, we illustrate the application and significance of these results by using them to predict single event upset event rates in a sample integrated circuit memory device, a 256 x 4-bit bipolar static RAM (93L422).     

Modeling solar proton access to geostationary spacecraft with geomagnetic cutoffs

Solar energetic particle (SEP) cutoffs at geosynchronous orbit are sensitive to moderate geomagnetic activity and undergo daily variations due to the day–night asymmetry of the magnetosphere. At geosynchronous orbit, cutoff rigidity also has a large directional dependence, with the highest cutoff rigidity corresponding to ions arriving from magnetic east and lowest cutoff rigidity corresponding to ions incident from the west. Consequently, during geomagnetically quiet periods, the SEP flux observed by an eastward facing particle detector is significantly lower than observed by a westward facing particle detector. During geomagnetically disturbed periods the cutoff is suppressed allowing SEPs access well inside of geosynchronous, so that the east–west SEP flux ratio approaches unity. Variations in the east–west SEP flux ratio observed by GOES Energetic Particle Sensors (EPS) have recently been reported by Rodriguez et al. (2010). In NOAA’s operational processing of EPS count rates into differential fluxes, the differential flux is treated as isotropic and flat over the energy width of the channel. To compare modeled SEP flux with GOES EPS observations, the anisotropy of the flux over the EPS energy range and field of view must be taken into account. A technique for making direct comparisons between GOES EPS observations and SEP flux modeled using numerically computed geomagnetic cutoffs is presented. Initial results from a comparison between modeled and observed flux during the 6–11 December 2006 SEP event are also presented. The modeled cutoffs reproduce the observed flux variations well but are in general too high.     

Single-event upset in geostationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite

This paper reports single-event upset (SEU) occurrence related to the space radiation environment in geostationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite. Most SEUs are measured in the inner radiation belt, indicating that they are mainly caused by trapped protons. Thus, the spatial distribution and the temporal variation of the SEU count correlate well with those of trapped protons. The peak SEU rate appears around L = 1.4. The transition point from SEUs caused by trapped protons to those caused by galactic cosmic rays is around L = 2.6. During the experiment period, increased SEU count was sometimes detected due to solar and geomagnetic events outside the inner radiation belt.     

Microelectronics effects as seen on CRRES.

A MicroElectronics Test Package (MEP) measured total dose degradation and single event upsets (SEUs) on 60 device types on the Combined Release and Radiation Effects Satellite (CRRES) in an 18 degrees inclination orbit between 350 km and 36000 km from July 1990 to October 1991. Simultaneous measurements of the high energy particle environment were used to make a direct cause and effect comparison of the energetic particle backgrounds and microelectronic performance characteristics. The galactic cosmic ray background for the period of the CRRES mission was at a minimum. The SEUs experienced from the cosmic ray background were correspondingly few in number, but surprisingly produced an equal probability of upset over an L-shell range of 8.5 Earth radii (RE) down to less than 3.0 RE. Cosmic ray induced upset frequencies in proton sensitive chips were over 2 orders of magnitude lower than those produced by protons in the heart of the inner proton radiation belts. Multiple upsets, those produced when a single particle upsets more than one memory location, were just as common from protons as from cosmic rays.     

80C31单粒子效应敏感度评估

采用串列静电加速器对同步轨道气象卫星扫描辐射计控制器用８０Ｃ３１微控制器进行了单粒子效应模拟试验，得到了器件的错误截面与ＬＥＴ关系曲线；根据试验结果，对器件在同步轨道重离子环境中的翻转率进行了预计。     

Energetic particle environment in near-Earth orbit.

The hazard of exposure to high doses of ionizing radiation is one of the primary concerns of extended manned space missions and a continuous threat for the numerous spacecraft in operation today. In the near-Earth environment the main sources of radiation are solar energetic particles (SEP), galactic cosmic rays (GCR), and geomagnetically trapped particles, predominantly protons and electrons. The intensity of the SEP and GCR source depends primarily on the phase of the solar cycle. Due to the shielding effect of the Earth's magnetic field, the observed intensity of SEP and GCR particles in a near-Earth orbit will also depend on the orbital parameters altitude and inclination. The magnetospheric source strength depends also on these orbital parameters because they determine the frequency and location of radiation belt passes. In this paper an overview of the various sources of radiation in the near-Earth orbit will be given and first results obtained with the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) will be discussed. SAMPEX was launched on 3 July 1992 into a near polar (inclination 82 degrees) low altitude (510 x 675 km) orbit. The SAMPEX payload contains four separate instruments of high sensitivity covering the energy range 0.5 to several hundred MeV/nucleon for ions and 0.4 to 30 MeV for electrons. This low altitude polar orbit with zenith-oriented instrumentation provides a new opportunity for a systematic study of the near-Earth energetic particle environment.     

The connection between space weather and Single Event Upsets in polar low earth orbit satellites

Space weather is driven and modulated by the activity in the Sun. Space weather events have the potential to inflict critical damage to space systems. Nowadays, space assets are essential in our basic needs, such as communications, cell phone networks, navigation systems, television and internet. Hence, understanding space weather dynamics and its effects on spacecraft is crucial for satellites engineers and satellite operators, in order to prevent and mitigate its impacts.In the last decade our Sun has erupted several times causing dozens of space weather events. Some of these led to satellite malfunctions and outages lasting from mere hours, up to days and weeks. This research is focused on two different space weather events, March 7–8, 2012, and September 6–10, 2017, that occurred during the last ten years and caused satellite anomalies that are related to an increase in the single event upsets rate. Single event upset is a bit flip in a memory device due to high energy particle interaction with the device sensitive volume. During these two periods, Eros B, a low Earth orbiting polar satellite detected an increased rate of single event upsets on two of its processing computers when the high energy proton flux was elevated. On both occasions X-class flares were detected, and the increased single event upsets count rate in Eros B took place only after the 100 MeV protons flux was three orders of magnitude above the background levels. In this research, Israeli satellite anomalies that were detected are first demonstrated.     

MONITORING OF ENERGETIC PARTICLE ENVIRONMENT INSIDE THE CHINA-BRAZIL EARTH RESOURCE SATELLITE

On 14 October 1999, the Chinese-Brazil earth resource satellite (CBERS-1) was launched in China. On board of the satellite there was an instrument designed at Peking University to detect the energetic particle radiation inside the satellite so the radiation fluxes of energetic particles in the cabin can be monitored continuously. Inside a satellite cabin, radiation environment consists of ether penetrated energetic particles or secondary radiation from satellite materials due to the interactions with primary cosmic rays.Purpose of the detectors are twofold, to monitor the particle radiation in the cabin and also to study the space radiation environment The data can be used to study the radiation environment and their effects on the electronics inside the satelhte cabin. On the other hand, the data are useful in study of geo-space energetic particle events such as solar proton events, particle precipitation and variations of the radiation belt since there should be some correlation between the radiation situation inside and outside the satellite.The instrument consists of two semi-conductor detectors for protons and electrons respectively. Each detector has two channels of energy ranges. They are 0.5-2MeV and ≥2MeV for electrons and 5-30MeV and 30-60MeV for protons. Counting rate for all channels are up to 104/(cm2@s)and power consumption is about 2.5 W. There are also the additional functions of CMOS TID (total integrated dose) effect and direct SEU monitoring. The data of CBMC was first sent back on Oct. 17 1999 and it's almost three years from then on. The detector has been working normally and the quality of data is good.The preliminary results of data analysis of CBMC not only reveal the effects of polar particle precipitation and radiation belt on radiation environment inside a satellite, but also show some important features of the geo-space energetic particle radiation.As one of the most important parameters of space weather, the energetic charged particles have great influences on space activities and ground tech nology. CBMC is perhaps the first long-term on-board special equipment to monitor the energetic particle radiation environment inside the satellite and the data it accnmulated are very useful in both satellite designing and space research.     

强磁暴、能量粒子暴与热层大气密度涨落之间的相关关系

利用1997-2007年由GOES8, GOES11和GOES12星载高能粒子探测器在地球同步轨道高度上所探测到的高能质子和高能电子通量探测数据以及高度560km左右星载大气密度探测器所得的热层大气密度探测数据, 统计分析了强地磁扰动、高能粒子通量跃变和热层大气密度涨落之间的相关关系, 初步获得强地磁扰动期间, 地球同步轨道(外辐射带外环)均出现了增幅大于三个数量级的高能质子通量(尤其是E>1MeV)强增强现象, 随后热 层大气密度强烈上涨, 表明三者之间是正相关关系. 在时间上地球同步轨道高能质子通量强增强现象先于日均Ap值(地磁活动程度)上涨约一天左右, 而热层大气密度强涨落现象又明显滞后于强地磁扰动事件.      

The YORP effect on the GOES 8 and GOES 10 satellites: A case study

The Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect is a proposed explanation for the observed rotation behavior of inactive satellites in Earth orbit. This paper further explores the YORP effect for highly asymmetric inactive satellites. Satellite models are developed to represent the GOES 8 and GOES 10 satellites, both of which are currently inactive in geosynchronous Earth orbit (GEO). A simple satellite model for the GOES 8 satellite is used to analyze the short period variations of the angular velocity and obliquity as a result of the YORP effect. A more complex model for the rotational dynamics of the GOES 8 and GOES 10 satellites are developed to probe their sensitivity and to match observed spin periods and states of these satellites. The simulated rotation periods are compared to observations for both satellites. The comparison between YORP theory and observed rotation rates for both satellites show that the YORP effect could be the cause for the observed rotational behavior. The YORP model also predicts a novel state for the GOES 8 satellite, namely that it could periodically fall into a tumbling rotation state. Recent observations of this satellite are consistent with this prediction.     

Solar particle events observed at Mars: dosimetry measurements and model calculations

During the period from March 13, 2002 to mid-September, 2002, six solar particle events (SPE) were observed by the MARIE instrument onboard the Odyssey Spacecraft in Martian Orbit. These events were observed also by the GOES 8 satellite in Earth orbit, and thus represent the first time that the same SPE have been observed at these separate locations. The characteristics of these SPE are examined, given that the active regions of the solar disc from which the event originated can usually be identified. The dose rates at Martian orbit are calculated, both for the galactic and solar components of the ionizing particle radiation environment. The dose rates due to galactic cosmic rays (GCR) agree well with the HZETRN model calculations.     

Solar flares,CMEs and solar energetic particle events during solar cycle 24

We present here a study of Solar Energetic Particle Events (SEPs) associated with solar flares during 2010–2014 in solar cycle 24. We have selected the flare events (≥GOES M-class), which produced SEPs. The SEPs are classified into three categories i.e. weak (proton intensity?≤?1?pfu), minor (1?pfu?<?proton intensity?<?10?pfu) and major (proton intensity?≥?10?pfu). We used the GOES data for the SEP events which have intensity greater than one pfu and SOHO/ERNE data for the SEP event less than one pfu intensity. In addition to the flare and SEP properties, we have also discussed different properties of associated CMEs.     

1 AU轨道SEP粒子通量的计算及与多卫星观测结果的比较

1 AU轨道上太阳高能粒子(Solar Energetic Particles,SEP)通量是空间天气的重要指标.将SEP两步传播方程的格林函数解进行数值化,模拟了2012年9月28日的SEP事件,首次计算了同一事件中GOES卫星与STEREO双星观测到的SEP通量变化过程.对GOES和STEREO-B观测点,计算所得SEP峰值I_max和峰值到达时间t_max与观测值符合较好;对STEREO-A,由于观测点与太阳活动源区间隔较大及太阳背面未知事件的影响,计算结果与观测存在一定差异.      

太阳高能粒子事件强度与相关双CME事件关系的两个事例

太阳高能粒子事件常伴随太阳耀斑和日冕物质抛射事件(Coronal Mass Ejections,CME)出现,由于太阳高能粒子事件的关键因素是双CME的相互作用,利用SOHO卫星观测的高能粒子强度、耀斑强度以及CME的相对高度与时间,通过高度与时间拟合得到的速度,分析了2001年4月15日和2005年1月20日的太阳高能粒子事件强度与相关双CME事件的关系,发现这两个太阳高能粒子事件中E ≥ 10MeV质子的强度与双CME事件无关.因此在这两次太阳高能粒子事件早期,E ≥ 10MeV质子的强度只与相关太阳耀斑和CME有关.      

Relative fluxes of shock and prompt peaks in SEP event time profiles

Peak fluxes are an important property of gradual solar energetic particle (SEP) event time profiles from both astro/heliophysical and applications perspectives. However, the peak flux in an event may occur at the event onset, or at the time of the interplanetary shock arrival (the ESP or energetic storm particles). This makes an important difference in the interpretation of the peak flux, and in any attempts to characterize or model it. This paper describes a study of SEP data sets from ACE, IMP-8 and GOES toward determining the relative properties of these peak fluxes for protons with energies near 1, 10, and 50 MeV. The results suggest that for gradual events with both peaks, the ESP peak often dominates at 1 MeV energies and is dominant about half the time at 10 MeV. Moreover, the prompt peak fluxes can be used to estimate the shock peak (ESP event) up to days ahead, especially in the lower energy range.     

质子引发的单粒子翻转率估算的研究

根据质子单粒子翻转事件的物理本质,及空间高能质子环境特性,给出了一种基于重离子单粒子翻转实验数据基础之上的估算质子引发的单粒子翻转的方法.利用这种方法计算了几种器件的翻转情况,与地面模拟实验及飞行观测结果符合得非常好.      

A new modeling method of solar energetic proton events for ISO specification

Solar energetic protons degrade performance and reliability of spacecraft systems due to single-event effects, total dose effects and displacement damage in electronics components including solar cells. On designing a solar cell panel, a total fluence of solar energetic protons (SEPs) which cause solar cell damage is needed to estimate power loss of the solar cells over mission life. Nowadays a solar panel area of spacecraft is increasing as spacecraft mission life becomes longer (15–18 years). Thus an accurate SEP model is strongly required for the cost-minimum design from the aerospace industry. The SEP model, JPL-91 proposed by Feynman et al., is currently used widely for solar cell designing. However, it is known that the JPL-91 model predicts higher fluences of protons than values actually experienced in space, especially after 7 years on orbit. In addition, the model is based on several assumptions, and also needs Monte-Carlo simulations for calculating fluences. In this study, we propose a new method for modeling SEPs especially focused on solar cell degradation. The newly-proposed method is empirical, which constructs a model based directly upon proton flux measurement data taken by instruments onboard spacecraft. This method has neither assumptions nor dependence on SEP event selection, both of which are needed in JPL-91. The model fluences derived from this method show lower fluences in longer missions compared to JPL-91. This method has been proposed to ISO (International Organization for Standardization) and has been discussed for a new standard SEP model.     

Cosmic radiation exposure of aircraft occupants on simulated high-latitude flights during solar proton events from 1 January 1986 through 1 January 2008

From 1 January 1986 through 1 January 2008, GOES satellites recorded 170 solar proton events. For 169 of these events, we estimated effective and equivalent dose rates and doses of galactic cosmic radiation (GCR) and solar cosmic radiation (SCR), received by aircraft occupants on simulated high-latitude flights. Dose rate and dose estimates that follow are for altitudes 30, 40, 50, and 60 kft, in that order.     

空间粒子辐射对卫星中集成芯片的影响

本文分析了在“风云一号(B)”气象卫星环境中各种粒子辐射在集成芯片临界体积中产生的能量沉积, 即LET(线性能量传输);得到了银河宇宙线1≤Z≤28、银河宇宙线异常成分(C、N、O、Ne、Ar、Fe)、内辐射带质子等产生的LET, 计算了其分别产生的单粒于事件(SEU)翻转率。