标题： 太阳耀斑硬X射线中的准周期变化研究 显示英文标题

标题： Investigation of quasi-periodic varaiations in hard X-rays of solar flares

摘要： 本文的目的是利用太阳耀斑中的硬X射线（HXRs）准周期振荡作为诊断工具，以研究突然的电子加速。我们选择了一些在硬X射线中显示出准周期振荡的耀斑，并且它们的环顶源在X射线图像中可以很容易被识别。我们考虑了磁流体静力驻波来解释观察到的X射线振荡。我们将这些X射线振荡解释为位于尖角状磁结构内的磁陷阱的振荡。这由振荡周期与环顶源大小之间的良好相关性得到证实。我们认为，振荡磁陷阱模型足以解释观测结果。在陷阱压缩期间，粒子被加速，而在其膨胀期间，来自色球蒸发的等离子体填充陷阱，这解释了在一系列强脉冲期间被加速的电子数量很大。我们提出的振荡磁陷阱模型的优势在于它能够同时解释电子加速的脉冲和其时间分布的准周期性。 显示英文摘要

摘要： The aim of the present paper is to use quasi-periodic oscillations in hard X-rays (HXRs) of solar flares as a diagnostic tool for investigation of impulsive electron acceleration. We have selected a number of flares which showed quasi-periodic oscillations in hard X-rays and their loop-top sources could be easily recognized in HXR images. We have considered MHD standing waves to explain the observed HXR oscillations. We interpret these HXR oscillations as being due to oscillations of magnetic traps within cusp-like magnetic structures. This is confirmed by a good correlation between periods of the oscillations and the sizes of the loop-top sources. We argue that a model of oscillating magnetic traps is adequate to explain the observations. During the compressions of a trap particles are accelerated, but during its expansions plasma, coming from chromospheric evaporation, fills the trap, which explains the large number of electrons being accelerated during a sequence of strong impulses. The advantage of our model of oscillating magnetic traps is that it can explain both the impulses of electron acceleration and quasi-periodicity of their distribution in time.