Acceleration of energetic particles by whistler waves in active space experiment with charged particle beams injection

In this paper the investigation of wave-particle interaction during simultaneous injection of electron and xenon ion beams from the satellite Intercosmos-25 (IK-25) carried out using the data of the double satellite system with subsatellite Magion-3 (APEX). Results of active space experiment devoted to the beam-plasma instability are partially presented in the paper Baranets et al. (2007). A specific feature of the experiment carried out in orbits 201, 202 was that charged particle flows were injected in the same direction along the magnetic field lines B₀ so the oblique beam-into-beam injection have been produced. Results of the beam-plasma interaction for this configuration were registered by scientific instruments mounted on the station IK-25 and Magion-3 subsatellite. Main attention is paid to study the electromagnetic and longitudinal waves excitation in different frequency ranges and the energetic electron fluxes disturbed due to wave-particle interaction with whistler waves. The whistler wave excitation on the 1st electron cyclotron harmonic via normal Doppler effect during electron beam injection in ionospheric plasma are considered.     

Injection of 40-kHz-modulated electron beam from the satellite: II. Excitation of electrostatic and whistler waves

Beam-plasma interaction effects are studied during the active space experiment with electron and Xe-ion beam injections in an ionospheric plasma. Permanent 40-kHz-modulated electron beam injection occurs simultaneously with a xenon-ion beam injected by the Hall-type plasma thruster operating in a square-pulse mode (100/50 s for a job/pause duration). The unusual behavior of the background charged particle fluxes and wave activity stimulated during the beam-plasma interaction have been registered by the scientific instruments onboard Intercosmos-25 station (IK-25) and Magion-3 subsatellite. The longitudinal and electromagnetic wave instabilities and their mutual relationship are considered in order to explain the observed effects. The excitation of electrostatic waves by the electron injection has been considered for different resonance conditions near the linear stability boundary. Beam-driven electromagnetic instability is responsible for the backward-propagating whistler waves excited via cyclotron resonance. Competition of these two beam instabilities is one of the subjects of the present study.     

Identification of seismic activity sources on the subsatellite track by ionospheric plasma disturbances detected with the Sich-2 onboard probes

Using a cylindrical Langmuir probe and the authors’ proprietary two-channel pressure transducer, ionospheric plasma parameter distributions along the orbit of the Sich-2 satellite (Ukraine, 2011–2012) were measured. This paper is concerned with identifying the space–time location of ionospheric plasma disturbance sources, including the epicenters of actual earthquakes (before or during the satellite flyover) and incipient earthquakes on the subsatellite track, from the measured distributions of the electron density and temperature and the neutral particle temperature along the satellite orbit. To do this, the measured ionospheric plasma parameter distributions are connected to the coordinates on the subsatellite track.It is shown that local disturbances in the electron density and temperature and neutral particle temperature distributions in the satellite orbit in the ionosphere may serve as indicators of seismic activity on the subsatellite track. The epicenters of incipient earthquakes may be set off from other plasma parameter disturbance sources associated with seismic activity using information provided by special monitoring and survey centers that monitor the current seismic situation.     

Negative body potential as result of modulated electron beam emission into ambient plasma

Two different processes play an important role during emission of pulsed electron beam from a satellite: the positive charging of the spacecraft by emitted electron current and the body neutralization by ambient plasma electrons (mainly in pauses between electron pulses).

The injection of modulated electron beam (pulses of 2μs duration, E=8keV, I=0.1A and 25μs repetition) was carried on in the APEX Project. A simple computer model of this process for APEX scenario was performed.

The results show that after primary positive charging (during gun operation) a significant negative charging (in pauses between pulses) caused by neutralization process by ambient plasma with fp>2MHz takes place.     

Observation of fundamental magnetoplasma emissions excited in magnetosphere by modulated electron beams

There were several cases when modulated electron beam had been injected from APEX satellite into an otherwise unmodified ionospheric plasma. The beams were formed from 2 μs pulses repeated at a rate of 40kHz. Injections took place in the altitude range 400–1100km over Europe. The onboard receiver connected to the dipole antenna swept the frequency interval 1–10 MHz in 1 sec. Due to a relatively narrow receiver bandwidth (15 kHz), moderate frequency step (50 kHz), slow changes of f_n and f_c (local electron plasma and gyro frequencies) fine structure of excited emissions was detected. In many cases, a very prominent doublet could be convincingly identified as a (f_n,f_u=sqrt(f_n^*f_n+f_c^*f_c)) band, with f_n practically equal to the local plasma frequency in the unperturbed ionosphere. Determination of plasma frequency is of prime importance in analysis of complex structures composed from various harmonics f_n,f_c,f_u. Complexity is manifested as coalescing of various harmonics with maxima shifted from nominal frequencies or splitting them into components due to mixing of local and propagation effects. Despite the existence of strong emissions on frequencies characteristic for the unperturbed ionosphere, very strong broadcasting transmissions are frequently cut off, even when the beam is directed upward. Most typical spectra are discussed.     

Response of the electron energy distribution to an artificially emitted electron beam: Apex experiment

The paper is based on the electron and ion energy spectra measurement on board the main spacecraft of the APEX mission. During the active phase of the experiment an intense electron beam was emitted from the main satellite. The basic cycle of the electron injection is formed by current pulses of different frequencies, duration and intensity. The spacecraft potential changes due to the gun operation were compensated by a low energy Xe plasma generator. The data show that the response of the environment to the beam emission depends not only on injection parameters but on the spacecraft position and orientation with respect to the magnetic field as well. The typical response is an increase of the intensity of the low energy (less than 1 keV) electrons in all directions. In addition, strong field aligned fluxes of electrons and/or ions are observed with energies below the gun energy. An attempt to classify different types of response and to find possible mechanisms which can explain the observed phenomena is made in the present paper.     

Electron beam experiments in Japanese satellites and rockets

Electron beam experiments in space that have been done and planned in Japan are reviewed. 200eV, 1mA electron beam is emitted from a satellite and several types of wave excitation such as UHF and ω_ce have been observed. The satellite potential and the energy spectrum of returning electrons are measured by Langmuir probes and electrostatic energy analyser. In rocket experiments of K-10-11, K-10-12, K-9M-57, K-9M-58, K-9M-61 and K-9M-66, several types of electron guns were used whose power ranges from 1mW to 1KW. The rocket potential was measured by Langmuir probes and floating probes and optical line emission measurement and wave measurements were also done. The rocket potential was not so high as expected from the balance with ionospheric plasma but strongly affected by the plasma production by the emitted electron beam and return electrons.     

快响SAR卫星零多普勒波束中心姿态机动策略研究

传统偏航牵引方法采用惯性系下卫星轨道6要素推导得出姿态机动参数,在此方法中仅控制卫星主轴方向多普勒频率为0Hz,无法补偿SAR天线安装偏差和波束在天线内的方位距离向离轴角引起的斜距偏差和多普勒频率偏移,不能满足SAR系统时序设计需求和快响SAR卫星在轨实时处理器性能要求。因此,提出了地心固定坐标系中SAR天线波束指向零多普勒面内目标方向的姿态机动策略,使快响SAR卫星在轨实际波束中心多普勒频率为0Hz。该策略首先计算了基于场景目标的SAR总体设计的精确时序参数和观测参数,然后在地心固定坐标系中建立了波束中心多普勒频率为0Hz的SAR天线波束三轴指向模型,推导得出卫星三轴指向和姿态机动参数,并通过Matlab对该策略进行了仿真验证。结果表明,该策略可将多普勒频率由地球自转引起的29kHz、天线与卫星安装偏差引起的360Hz和波束方位向离轴角引起的3950Hz补偿至0Hz,同时将由天线与卫星安装偏差和波束距离向离轴角综合引起的波束中心偏离目标的斜距偏差6.28km补偿至米的量级。     

Effect of HF emission of the topside sounder transmitter aboard the COSMOS-1809 satellite on the ionospheric plasma

The experiment on investigation of effect of the HF emission (300 W) by the dipole antenna on the ionospheric plasma was carried out onboard the COSMOS-1809 satellite (1987). The sounder accelerated particles (SAP) at the electron cyclotron harmonics n · ω_cs and in the frequency region of antenna resonance were detected by the charged particle spectrometer.     

基于冲量变轨原理的地球同步卫星有限推力变轨策略

  推力有限时,地球同步轨道卫星在远地点变轨的弧段很长,会导致较多的燃料消耗。基于冲量变轨原理,研究了地球同步轨道卫星远地点有限推力多次变轨问题,提出了具有星下点约束的最省燃料变轨方案,给出了每次变轨的推力方向和点火起止时刻及最优中间过渡轨道。仿真结果验证了该方案的有效性。     

载人航天器与伴随卫星间射频系统电磁兼容性分析方法

对载人航天器与伴随卫星间射频设备的电磁干扰问题进行了研究，根据射频系统的收发参数建立了电磁干扰安全裕度模型，分析了伴随卫星发射天线对载人航天器接收天线的等效干扰。从保证载人航天器与伴随卫星在轨电磁兼容的角度，得到了航天器间能够兼容工作的最小相对距离计算方法。研究结果表明，所提出的分析方法能够对伴飞任务航天器间的电磁干扰风险进行预测，可为飞行任务的顺利完成提供技术支持。     

Plasma wave observations during electron gun experiments on ISEE-1

The ISEE-1 electron guns were operated during the final orbits of ISEE-1 in 1987 in tests designed to study the stimulation of plasma waves. The guns were operated in modes which varied from 10-μA, at 10-eV, to 100-μA at 45-eV. Experiments were run on inbound orbits, while moving from the solar wind into perigee on the dusk side. A broadband emission was generally found from 0.1–10-kHz (e.g. below the plasma frequency). Next, a strong signal was typically induced at about 80-kHz, well above the ambient plasma frequency. This is interpreted as being the plasma frequency associated with the “beam” electrons. There were occasionally intensifications of the naturally occurring signals at the electron cyclotron frequency and the electron plasma frequency (or upper hybrid resonance).     

数据中继卫星的频率和轨道

描述了典型数据中继卫星系统的通信链路;给出了这些系统在用的和计划使用的无线电频谱;讨论了影响数据中继卫星频段选择的因素。为了防止其他中继卫星系统对一个中继卫星系统的有害干扰,可以使用如频率错开、极化分辨、经度分离,甚至采用伪码分辨的方法。     

应用LTCC工艺的基片集成波导开关矩阵

文章首次应用低温共烧陶瓷(Low-temperature Co-fired Ceramic,LTCC)工艺和基片集成波导(Substrate Integrated Waveguide,SIW)技术,实现了星载高频段开关矩阵。首先详细讨论了不同层间SIW 通道的连接过渡方式,并分析了通道间隔离度特性。在此基础之上,应用单刀双掷开关芯片作为通道选择器件,多层SIW 通道作为射频信号传输、连接和交叉通道,实现了基于LTCC技术的高隔离度、低插损的K 频段4x4开关矩阵,在20~21GHz频带内实测的通道插入损耗小于8dB,通道间隔离度大于38dB。从而解决LTCC高频开关矩阵设计受限于传统带状线特性而导致得到的开关矩阵插入损耗大、隔离度低的技术瓶颈。     

基于ZnO阵列的银表面二次电子发射抑制技术

随着卫星有效载荷的射频功率越来越大,传统的微放电抑制方法已经无法满足大功率卫星有效载荷的需求。降低大功率射频部件内表面的二次电子发射系数是抑制微放电效应的重要方法之一,通过在金属银表面构造纳米量级ZnO阵列,实现了纳米尺度银陷阱结构的制备,研究了晶种制备方式、锌盐浓度对ZnO阵列生长的影响。结果表明,采用紫外照射法制备晶种获得的ZnO阵列在样片表面分布均匀,提高锌盐浓度可改善ZnO阵列的分布均匀性。分析了ZnO阵列排列密度对银膜构筑的影响,发现在低密度的ZnO阵列上更加容易镀覆金属银。因此,获得了镀银表面基于ZnO阵列的陷阱结构制备的工艺技术,实现金属银表面二次电子发射系数最大值降低36.3%。     

Registration of ELF waves in rocket-satellite experiment with plasma injection

Two rocket experiments KOMBI-SAMA with plasma injection at height 100–240 km were performed in August 1987 in the region of Brazilian magnetic anomaly (L = 1.25). The launching time of the rocket was determined so that plasma injection was at the time when satellite COSMOS 1809 passed as close as possible to magnetic tube of injection. Caesium plasma jet was produced during ≥ 300 s by electric plasma generator separated from the payload. By diagnostic instruments on board of the rocket and the satellite were registered energetic particle fluxes and plasma wave activities stimulated by plasma injection. When the satellite passed the geomagnetic tube intersecting the injection region an enhancement of ELF emission at 140 Hz, 450 Hz by 2 times was registered on board the satellite. An enhancement of energetic particles (E > 40 keV) flux by 4–5 times was registered on board the rocket. Observed ELV emission below 100 Hz is interpreted as generation of oblique electromagnetic ion-cyclotron waves due to drift plasma instability at the front of the plasma jet.     

航天器介质放电脉冲频谱特征实验研究

空间电子辐射环境下,航天器介质的充放电效应是威胁航天器安全的重要因素.介质放电现象除与材料参数及构型相关外,还与空间电子环境密切相关.本文通过电子枪和Sr90放射源在地面实验装置上模拟空间电子辐照环境,测试了环氧树脂、聚四氟乙烯、聚酰亚胺等常见空间材料在不同温度、不同电子能量和电子束流强度影响下的放电脉冲,并对放电电流脉冲和电场脉冲进行频谱分析.实验分析结果表明,介质材料的放电电流脉冲频谱具有明显的单峰结构,该峰值与材料厚度和入射电子能量相关,但受材料温度和辐照束流强度影响不大.      

X-ray, γ-emission and energetic particles in near-Earth space as measured by CORONAS-F satellite: From maximum to minimum of the last solar cycle

The Russian solar observatory CORONAS-F was launched into a circular orbit on July 31, 2001 and operated until December 12, 2005. Two main aims of this experiment were: (1) simultaneous study of solar hard X-ray and γ-ray emission and charged solar energetic particles, (2) detailed investigation of how solar energetic particles influence the near-Earth space environment. The CORONAS-F satellite orbit allows one to measure both solar energetic particle dynamics and variations of the solar particle boundary penetration as well as relativistic electrons of the Earth’s outer radiation belt during and after magnetic storms. We have found that significant enhancements of relativistic electron flux in the outer radiation belt were observed not only during strong magnetic storms near solar maximum but also after weak storms caused by high speed solar wind streams. Relativistic electrons of the Earth’s outer radiation belt cause volumetric ionization in the microcircuits of spacecraft causing them to malfunction, and solar energetic particles form an important source of radiation damage in near-Earth space. Therefore, the present results and future research in relativistic electron flux dynamics are very important.     

Appearance of VLF and ELF-noises in topside ionosphere under the action of high power radio wave from data of satellite intercosmos-24

Results of a satellite experiment are presented on detection of VLF and ELF-waves excited by irradiation of the night ionosphere F-region by the field of a nonmodulated high-power radio wave. The excited VLF and ELF-waves have been detected at the topside ionosphere heights h=500–1000 km in the frequency bands 8 kHz相似文献   

从空间飞行器入射进电离层的调制电子束产生的高频波辐射

在主动束-等离子体试验中,调制电子束从空间飞行器入射进电离层等离子体将会产生电磁波辐射,在不同试验条件下电磁波辐射机理也不一样,由电子束纵向约束性产生电磁波辐射是其中之一.对半无界稀薄调制电子束从空间飞行器入射进电离层等离子体时所产生的波现象进行了理论分析和数值计算.结果表明,当调制电子束沿磁力线入射时,会在电离层等离子体中产生高频电磁波辐射,该辐射主要集中在垂直于入射电子束运动方向的平面内.