标题： 日冕物质抛射驱动激波的孤立能谱性质 显示英文标题

标题： Energy Spectral Property in an Isolated CME-driven Shock

摘要： 来自多艘航天器的观测表明，在一些由大尺度日冕物质抛射（CME）驱动的激波中，存在能量谱在1-10 MeV范围内的“拐折”。然而，由于计算成本高昂，数值模型很难模拟这一特性。本文的重点是通过孤立CME驱动激波的蒙特卡罗粒子模拟来分析这些能量谱“拐折”现象。以2006年12月14日由CME驱动的激波为例，我们研究了这种能量谱特性的形成机制。为此，我们在孤立激波模型中采用不同的散射时间值，以期获得可能超出“拐折”能量范围的最高能量“尾部”。然而，我们并未发现超出“拐折”能量范围的最高能量“尾部”，而是发现最高能量“尾部”在接近5 MeV能量范围内趋于饱和。因此，我们认为在孤立激波中存在一个能量谱“截止”。如果没有与其他激波的相互作用，则不会形成能量谱“拐折”特性。 显示英文摘要

摘要： Observations from multiple spacecraft show that there are energy spectral "breaks" at 1-10MeV in some large CME-driven shocks. However, numerical models can hardly simulate this property due to high computational expense. The present paper focuses on analyzing these energy spectral "breaks" by Monte Carlo particle simulations of an isolated CME-driven shock. Taking the Dec 14 2006 CME-driven shock as an example, we investigate the formation of this energy spectral property. For this purpose, we apply different values for the scattering time in our isolated shock model to obtain the highest energy "tails", which can potentially exceed the "break" energy range. However, we have not found the highest energy "tails" beyond the "break" energy range, but instead find that the highest energy "tails" reach saturation near the range of energy at 5MeV. So, we believe that there exists an energy spectral "cut off" in an isolated shock. If there is no interaction with another shock, there would not be formation of the energy spectral "break" property.