Counterstreaming beams and flat-top electron distributions observed with Langmuir, Whistler, and compressional Alfvén waves in earth's magnetic tail.
Counterstreaming beams and flat-top electron distributions observed with Langmuir, Whistler, and compressional Alfvén waves in earth's magnetic tail.
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DOI：
10.1103/physrevlett.102.075003
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发表时间：
2008-12
影响因子：
8.6
通讯作者：
A. Teste;G. Parks
中科院分区：
文献类型：
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作者：
A. Teste;G. Parks
在地球等离子体层（PS）中获得了波粒相互作用的相关新线索。在Cluster航天器上进行的等离子体测量表明，PS边界层中的宽带（约2-6 kHz）静电发射与冷逆流电子以5-12 × 10(3) km s（-1）的速度流过热麦克斯韦等离子体有关。在电流片（CS）中，电磁哨声模式波（约10- 80hz）和压缩alfvsamn波（< 2hz）被检测到具有平顶电子分布，其截止速度约为15-17x10(3) km s（-1）。这些波在中央CS中受到抑制，其中|B|<或=1.5 nT，等离子体β约为100，电子分布各向同性。三种机制在起作用：β依赖的低混合漂移不稳定性（LHDI）， LHD波沿着B场加速电子和回旋加速器共振不稳定性触发的哨声模式发射。
Relevant new clues to wave-particle interactions have been obtained in Earth's plasma sheet (PS). The plasma measurements made on Cluster spacecraft show that broadband (approximately 2-6 kHz) electrostatic emissions, in the PS boundary layer, are associated with cold counterstreaming electrons flowing at 5-12x10(3) km s(-1) through hot Maxwellian plasma. In the current sheet (CS), electromagnetic whistler mode waves (approximately 10-80 Hz) and compressional Alfvén waves (<2 Hz) are detected with flat-topped electron distributions whose cutoff speeds are approximately 15-17x10(3) km s(-1). These waves are damped in the central CS where |B|<or=1.5 nT, plasma beta approximately 100, and electron distributions isotropic. Three mechanisms are at work: the beta-dependent lower hybrid drift instability (LHDI), acceleration of electrons along the B field by the LHD waves and whistler mode emissions triggered by the cyclotron resonance instability.