On the role of injection in kinetic approaches to non‐linear particle acceleration at non‐relativistic shock waves
On the role of injection in kinetic approaches to non‐linear particle acceleration at non‐relativistic shock waves
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DOI：
10.1111/j.1365-2966.2005.09227.x
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发表时间：
2005-05
影响因子：
4.8
通讯作者：
S. Gabici;P. Blasi;Giulia Vannoni
中科院分区：
文献类型：
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作者：
S. Gabici;P. Blasi;Giulia Vannoni
由一阶费米过程加速的粒子在激波阵面上的动力学反应可以在既考虑激波流体动力学又考虑加速粒子输运的动力学模型中确定。这些模型预测了多种解决方案的出现，所有这些都是物理上允许的。在这里，我们在一个简单的现象学配方的框架内讨论注入在选择真实解决方案中的作用，这是有时被称为热泄漏的变体。在这一背景下，我们证明了多个解基本上消失了，当它们存在时，它们被限制在参数的相当特殊的值。我们还给出了宇宙线修正激波下粒子加速效率的定量计算，并确定了在最大动量时向下游平流的能量和从上游无穷大逃逸的粒子所占的比例。文中还讨论了粒子有效加速对激波加热的影响。
The dynamical reaction of the particles accelerated at a shock front by the first-order Fermi process can be determined within kinetic models that account for both the hydrodynamics of the shocked fluid and the transport of the accelerated particles. These models predict the appearance of multiple solutions, all physically allowed. We discuss here the role of injection in selecting the real solution, in the framework of a simple phenomenological recipe, which is a variation of what is sometimes referred to as thermal leakage. In this context we show that multiple solutions basically disappear and when they are present they are limited to rather peculiar values of the parameters. We also provide a quantitative calculation of the efficiency of particle acceleration at cosmic ray modified shocks and we identify the fraction of energy which is advected downstream and that of particles escaping the system from upstream infinity at the maximum momentum. The consequences of efficient particle acceleration for shock heating are also discussed.