The critical intensity of Alfven waves for electron-cyclotron maser to favor the O-mode emission

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 太阳和太阳系等离子体研究团组

	The critical intensity of Alfven waves for electron-cyclotron maser to favor the O-mode emission
	Zhao, G. Q.1; Feng, H. Q.1; Wu, D. J.2
刊名	PHYSICS OF PLASMAS
	2015-10-01
卷号	22 期号:10
英文摘要	The presence of Alfven waves (AWs) has been found to significantly affect electron-cyclotron maser (ECM), which is a powerful emission mechanism in astrophysical plasmas. A conventional ECM driven by power-law electrons with a lower-energy cutoff generally prefers X-mode emission to O-mode. In particular, the ECM possibly favors O-mode because it is dependent on the relative intensity of the present AWs, xi = B-w(2)/B-0(2), where B-w and B-0 are the field strength of AWs and the ambient magnetic field, respectively. This paper, for the first time, quantitatively investigates the critical relative intensity of AWs, above which the ECM becomes to favor the O-mode emission. It is found that the critical intensity depends on velocity distribution function features of energetic electrons, as well as on ambient plasma parameters. In principle, the critical intensity is in the order of xi similar to 10(-2) for power-law electrons with a lower energy cutoff, when the fundamental wave in X-mode is suppressed. Moreover, the incorporation of the loss cone distribution caused by the magnetic mirror effect can considerably lower the critical intensity of AWs. This study contributes to the understanding of solar type I radio storm emissions, which are dominated by the O-mode. (C) 2015 AIP Publishing LLC.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Physics, Fluids & Plasmas
研究领域[WOS]	Physics
关键词[WOS]	POWER-LAW ELECTRONS ; ENERGY CUTOFF BEHAVIOR ; SOLAR-WIND ; CORONAL LOOPS ; RADIO-BURSTS ; NONTHERMAL ELECTRONS ; INSTABILITY ; RADIATION ; ACCELERATION ; TURBULENCE
收录类别	SCI
语种	英语
WOS记录号	WOS:000364403600021
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/16064]
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.Luoyang Normal Univ, Inst Space Phys, Luoyang, Peoples R China 2.Chinese Acad Sci, Purple Mt Observ, Nanjing, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Zhao, G. Q.,Feng, H. Q.,Wu, D. J.. The critical intensity of Alfven waves for electron-cyclotron maser to favor the O-mode emission[J]. PHYSICS OF PLASMAS,2015,22(10).
APA	Zhao, G. Q.,Feng, H. Q.,&Wu, D. J..(2015).The critical intensity of Alfven waves for electron-cyclotron maser to favor the O-mode emission.PHYSICS OF PLASMAS,22(10).
MLA	Zhao, G. Q.,et al."The critical intensity of Alfven waves for electron-cyclotron maser to favor the O-mode emission".PHYSICS OF PLASMAS 22.10(2015).