LOWER HYBRID-RESONANCE ACCELERATION OF ELECTRONS AND IONS IN SOLAR-FLARES AND THE ASSOCIATED MICROWAVE EMISSION

NCU Institutional Repository > 地球科學學院 > 太空科學研究所 > 期刊論文 > Item 987654321/27541

請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/27541

題名:	LOWER HYBRID-RESONANCE ACCELERATION OF ELECTRONS AND IONS IN SOLAR-FLARES AND THE ASSOCIATED MICROWAVE EMISSION
作者:	MCCLEMENTS,KG;BINGHAM,R;SU,JJ;DAWSON,JM;SPICER,DS
貢獻者:	太空科學研究所
關鍵詞:	X-RAY BURSTS;STOCHASTIC ACCELERATION;RADIO SPIKES;INSTABILITIES;TURBULENT;SPECTRA;DISTRIBUTIONS;PRECIPITATION;SIMULATION;PARTICLES
日期:	1993
上傳時間:	2010-06-29 18:40:36 (UTC+8)
出版者:	中央大學
摘要:	Nonlinear wave processes at the lower hybrid resonance frequency are extremely important in transferring energy between different particle populations and fields in both astrophysical and laboratory plasmas. In this paper we investigate particle acceleration resulting from the relaxation of unstable ion ring distributions, producing strong wave activity at the lower hybrid resonance frequency, which collapses to produce energetic electron and ion tails. We apply the results to the problem of explaining energetic particle production in solar flares. There are several mechanisms whereby unstable ion distributions could be formed in the solar atmosphere, including reflection at perpendicular shocks, tearing mode reconnection, and loss cone depletion. Numerical simulations of ion ring relaxation processes, obtained using a 2 1/2-dimensional fully electromagnetic, relativistic particle in cell code are presented. The results show the simultaneous acceleration of electrons to energies in the range 10-500 keV, and ions to energies of the order of 1 MeV. The electron flux is sufficiently high to account for flare hard X-ray emission, on the basis of the thick-target model. The MeV ions have insufficient energy to account for gamma-ray line emission in the 4-6 MeV range, but they provide a seed population for further acceleration, which could result from the presence of either lower hybrid or MHD wave turbulence. Particle energization is observed to occur inside elongated nonlinear wavepackets, indicating that the acceleration process is highly filamented. Our simulations also show wave generation at the electron cyclotron frequency. We suggest that this process could play a role in the production of solar millisecond radio spikes, which are normally attributed to the cyclotron maser instability.
關聯:	ASTROPHYSICAL JOURNAL
顯示於類別:	[太空科學研究所 ] 期刊論文

文件中的檔案:

檔案	描述	大小	格式	瀏覽次數
index.html		0Kb	HTML	631	檢視/開啟

在NCUIR中所有的資料項目都受到原著作權保護.

社群 sharing

資料載入中.....