Electron cyclotron maser (ECM) emission is an important coherent emission mechanism for the direct amplification of electromagnetic waves by nonthermal electrons in a magnetized plasma. This paper will report on our recent study on ECM emission by fast electron beams with moderately relativistic energy. The results show that, similar to the spontaneous emission by the magnetic cyclotron motion of energetic electrons in a magnetic field, the coherent emission also exhibits the characteristic of a gradual transition from harmonic emission to continuous emission as the energy of the energetic electrons increases from subrelativistic to relativistic. The effects of the characteristic beam electrons energy (Ec) and the plasma-to-cyclotron frequency ratio (ωpe/ωce) on the growth rate, the peak-value frequency, and the spectral width are discussed further. These results are helpful for us to understand phenomena associated with astrophysical radio bursts.

中文翻译：

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具有中等相对论电子的电子回旋加速器


电子回旋加速器 （ECM） 发射是一种重要的相干发射机制，用于磁化等离子体中的非热电子直接放大电磁波。本文将报告我们最近对具有中等相对论能量的快速电子束发射 ECM 的研究。结果表明，与高能电子在磁场中磁回旋运动的自发发射类似，随着高能电子的能量从亚相对论增加到相对论，相干发射也表现出从谐波发射逐渐过渡到连续发射的特征。进一步讨论了特征束电子能量 （Ec） 和等离子体与回旋加速器频率比 （ωpe/ωce） 对生长速率、峰值频率和光谱宽度的影响。这些结果有助于我们理解与天体物理射电暴相关的现象。