The effect of electron beams on cyclotron maser emission excited by lower-energy cutoffs
The effect of electron beams on cyclotron maser emission excited by lower-energy cutoffs
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DOI：
10.1063/1.4948713
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发表时间：
2016-05
影响因子：
2.2
通讯作者：
Guoqing Zhao;H. Feng;D. J. Wu
中科院分区：
文献类型：
--
作者：
Guoqing Zhao;H. Feng;D. J. Wu
电子回旋脉塞（ECM）是天体物理学中最重要的辐射机制之一，它可以被幂律电子的低能截止有效激发。这些非热电子可能作为定向准直束沿着环境磁场传播。本文研究了电子束的电子对抗技术，着重研究了电子束的电子对抗效应。结果表明，电子束特征的ECM的发射特性的依赖性。随着束流动量的增加，非常模的最大增长率（X2）迅速减小，而普通模的增长率（O1）变化不大。特别是当束流动量足够大时，普通模可以克服非常模，成为增长最快的模。该研究是低能截止驱动的ECM的传统研究的扩展，可能有助于更好地理解以普通模辐射为主的太阳I型射电爆发的辐射过程。
Electron-cyclotron maser (ECM) is one of the most important emission mechanisms in astrophysics and can be excited efficiently by lower-energy cutoffs of power-law electrons. These non-thermal electrons probably propagate as a directed collimated beam along ambient magnetic fields. This paper investigates the ECM, in which the effect of electron beams is emphasized. Results show the dependence of emission properties of the ECM on the beam feature. The maximum growth rate of the extraordinary mode (X2) rapidly decreases as the beam momentum increases, while the growth rate of the ordinary mode (O1) changes slightly. In particular, the ordinary mode can overcome the extraordinary mode and becomes the fastest growth mode once the beam momentum is large enough. This research presents an extension of the conventional studies on ECM driven by lower-energy cutoffs and may be helpful to understand better the emission process of solar type I radio bursts, which are dominated by the ordinary mode emission.