Simultaneous observations of electrons (E > 45 keV) at 2000‐kilometer altitude and at 100,000 kilometers in the magnetotail
Simultaneous observations of electrons (E > 45 keV) at 2000‐kilometer altitude and at 100,000 kilometers in the magnetotail
复制标题
在磁尾中同时观测2000公里高度和100,000公里处的电子（E > 45 keV）
DOI：
10.1029/ja073i023p07339
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发表时间：
1968
影响因子：
--
通讯作者：
C. Rao
中科院分区：
文献类型：
--
作者：
E. W. Hones;S. Singer;C. Rao
爱荷华大学的印第安4号卫星和Vela卫星2A、2B、3A和3B上的盖格计数器提供了在地球极光和极地地区~ 2000公里高度和磁尾等离子体层~ 17地球半径（RE）处的高能电子通量（Ee bbbb45 kev）的同时测量。本文所讨论的资料是在1965年3月、4月、9月和10月，印第安4号在磁地方时1600 ~ 2400和0400 ~ 1200mlt期间穿过北极光带。印第安的测量结果证实了最近的一项报告，即在上午晚些时候，在极光区午夜部分的磁湾开始后不久，外层带的电子峰值通量通常会大幅增加。此外，它们表明，外层带的傍晚部分不会以这种方式迅速响应海湾。这种响应的差异支持了这样一种观点，即增强外带早晨扇区的电子是由某个作用于磁层午夜扇区的过程注入的。船帆座的测量结果证实了早先的一份报告，即在等离子体薄片中出现了一种本质上各向同性的高能电子通量，通常在一个海湾的峰值之后。此外，Vela和Injun 4的同步测量结果表明，在一个海湾后等离子体片中的电子通量通常比在同一海湾后的外层区域达到的峰值通量要小得多。的延迟出现电子在磁尾及其强度相对较低暗示的激发过程行为不是遥远的尾巴,但比17再保险接近地球。建议电子激发(连同周围等离子体)的一般加热发生在极光和/或外围区管的力在湾和这些管子不延长到17到尾巴在通电过程中。热等离子体移动到遥远的尾部标志着一个海湾开始恢复，并导致在尾部看到的高能电子爆发。因此，远尾并不是高能（45kev）外带电子的来源，而是产生它们的过程的附加吸收。根据这些和其他观察结果，有人认为高能电子的产生主要是由磁场线合并以外的其他过程引起的。
Geiger counters on the University of Iowa's Injun 4 satellite and on Vela satellites 2A, 2B, 3A, and 3B have provided simultaneous measurements of energetic electron fluxes (Ee > 45 kev) at ∼2000-km altitude over the auroral and polar regions of the earth and at ∼17 earth radii (RE) in th plasma sheet of the magnetotail. The data discussed here were obtained in March, April, September, and October 1965 periods when Injun 4 crossed the northern auroral zone between 1600 and 2400 magnetic local time (MLT) and between 0400 and 1200 MLT. The Injun measurements confirm a recent report that the peak flux of electrons in the outer belt in the late morning hours often is substantially increased shortly after the onset of a magnetic bay in the midnight sector of the auroral zone. They show, in addition, that the early evening sector of the outer belt does not respond promptly in this way to a bay. This difference in response supports the view that the electrons that enhance the morning sector of the outer belt are injected by some process acting in the midnight sector of the magnetosphere. The Vela measurements confirm an earlier report that an essentially isotropic flux of energetic electrons appears in the plasma sheet, generally after the peak of a bay. Furthermore, the concurrent measurements by Vela and Injun 4 show that the flux of electrons in the plasma sheet after a bay is usually much less intense than the peak flux attained in the outer zone after the same bay. Both the delayed appearance of the electrons in the magnetotail and their relatively lower intensity imply that the energization process acts not in the very distant tail, but closer to the earth than 17 RE. It is suggested that electron energization (along with a general heating of the ambient plasma) takes place within the auroral and/or outer-zone tubes of force during a bay and that these tubes do not extend as far as 17 RE into the tail during the energization process. Movement of the hot plasma to the distant tail signals the start of recovery of a bay and results in the bursts of energetic electrons seen in the tail. Thus, the distant tail is not a source of energetic (>45-kev) outer-belt electrons, but an additional sink for the process that generates them. It is argued, on the basis of these and other observations, that some process other than merging of magnetic field lines is primarily responsible for generation of the energetic electrons.