ELECTRON CYCLOTRON MASER INSTABILITY IN SPACE PLASMAS WITH KAPPA LOSS-CONE DISTRIBUTION

Journal Article · Wed Feb 01 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/745/2/134· OSTI ID:22011904

Tang, J F; Wu, D J ^[1]

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1. Purple Mountain Observatory, CAS, Nanjing 210008 (China)

It is well known that non-thermal electrons, often modeled by the kappa distribution, are ubiquitously observed in space. Kappa-type distributions have been widely discussed in various plasma environments. On the other hand, when these non-thermal electrons are trapped by magnetic fields in space they frequently have a loss-cone distribution in velocity space. In this paper, we investigated the growth rates of electron cyclotron maser (ECM) instability in space plasmas by using a kappa loss-cone distribution. Based on the cold plasma assumption and weakly relativistic approximation, the results show that non-thermal electrons with such a distribution can excite ECM emission efficiently. The growth rates of O1 and X2 modes both increase with the kappa spectral index ({kappa}) but the growth rate of X2 mode increases slightly more rapidly than that of O1 mode. The present analysis also shows that the growth rates increase rapidly with the loss-cone index {sigma} for {sigma} < 10 but increase comparatively slowly for larger {sigma} values.

• OSTI ID: 22011904
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 745; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
ASTROPHYSICS
COLD PLASMA
EMISSION
LOSS CONE
MAGNETIC FIELDS
MASERS
RELATIVISTIC RANGE
SUN