Kinetic Alfven wave instability driven by a field-aligned current in high-beta plasmas

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	Kinetic Alfven wave instability driven by a field-aligned current in high-beta plasmas
	Chen, L.1,2 ; Wu, D. J.1; Hua, Y. P.1,2
刊名	PHYSICAL REVIEW E
	2011-10-19
卷号	84 期号:4 页码:046406
关键词	CORONAL LOOP OSCILLATIONS ELECTRON ACCELERATION NONLINEAR EXCITATION TRANSITION-REGION HOSE INSTABILITY SOLAR ATMOSPHERE MODE CONVERSION MAGNETIC-FIELD CURRENT SHEETS HEAVY-IONS
ISSN号	1539-3755
英文摘要	Including the ion-gyroradius effect, a general low-frequency kinetic dispersion equation is presented, which simultaneously takes account of a field-aligned current and temperature anisotropy in plasmas. Based on this dispersion equation, kinetic Alfven wave (KAW) instability driven by the field-aligned current, which is carried by the field-aligned drift of electrons relative to ions at a drift velocity V-D, is investigated in a high-beta plasma, where beta is the kinetic-to-magnetic pressure ratio in the plasma. The numerical results show that the KAW instability driven by the field-aligned current has a nonzero growth rate in the parallel wave-number range 0 < k(z) < k(z)(u), where the growth rate reaches a maximum at k(z) similar to k(z)(u)/2. On the other hand, in the perpendicular wave-number range 0 < k(perpendicular to) < k(perpendicular to)(u) the growth rate monotonously decreases with the wave number k(perpendicular to) from a maximum at k(perpendicular to) = 0 to zero at k(perpendicular to) = k(perpendicular to)(u). In particular, the upper boundaries of the growing ranges in the wave-number space, k(z)(u) and k(perpendicular to)(u), as well as the growth rate increase with V-D, imply that there are wider growing ranges and larger growth rate for larger drift velocities. Including the temperature anisotropy of plasma particles, the result shows that the instability conditions for these two driven mechanisms are both modified considerably, in which the growing parametric ranges of KAWs widen. The results have potential importance in understanding the physics of space and astrophysical plasma active phenomena since the field-aligned current, also called the Birkeland current, is one of the most active factors in plasma phenomena.
学科主题	Physics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Physics, Fluids & Plasmas ; Physics, Mathematical
研究领域[WOS]	Physics
关键词[WOS]	CORONAL LOOP OSCILLATIONS ; ELECTRON ACCELERATION ; NONLINEAR EXCITATION ; TRANSITION-REGION ; HOSE INSTABILITY ; SOLAR ATMOSPHERE ; MODE CONVERSION ; MAGNETIC-FIELD ; CURRENT SHEETS ; HEAVY-IONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000296526600004
公开日期	2012-08-07
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/4503]
专题	紫金山天文台_太阳和太阳系等离子体研究团组
作者单位	1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 2.Chinese Acad Sci, Grad Sch, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Chen, L.,Wu, D. J.,Hua, Y. P.. Kinetic Alfven wave instability driven by a field-aligned current in high-beta plasmas[J]. PHYSICAL REVIEW E,2011,84(4):046406.
APA	Chen, L.,Wu, D. J.,&Hua, Y. P..(2011).Kinetic Alfven wave instability driven by a field-aligned current in high-beta plasmas.PHYSICAL REVIEW E,84(4),046406.
MLA	Chen, L.,et al."Kinetic Alfven wave instability driven by a field-aligned current in high-beta plasmas".PHYSICAL REVIEW E 84.4(2011):046406.