自由能密度上限及毫秒级射电尖峰的“饱和”机制

本文首先介绍了热力学自由能上限的普遍公式及其推导思想,然后应用于非热电子束的具体形式,从而估计太阳射电活动中的毫秒级尖峰辐射的“饱和”能量;在此基础上,进一步为饱和时间问题作一般性的讨论;最后,在把尖峰“饱和”的几种机制进行了比较之后提出:由于尖峰能量远未达到非线性饱和的水平,因此,由某种外部因素(例如加速机制等)所导致的高能电子束的非均匀性可能是一种较为合理的模型。

THE UPPER LIMIT OF THE THERMODYNAMIC FREE ENERGY AND THE SATURATION MECHANISMS OF THE MILLISECOND RADIO SPIKES

In this paper, the physical concept and derivation of a general formula for the upper limit of the thermodynamic free energy are introduced. Then this formula is used to estimate the saturation energy of the millisecond radio spikes in solar activities. Moreover, the estimation of saturation time is discussed generally. At last, some different mechanisms for the saturation of solar radio spikes are compared. It is supposed that the emissive power of radio spikes is much lower than the nonlinear saturation level. So, the ununiformity of the electron beam, which results from some external causes, such as the mechanism of particle acceleration, may be a reasonable model for the saturation of radio spikes.