Electron heating and acceleration in the shock transition region: Background plasma parameter dependence
Electron heating and acceleration in the shock transition region: Background plasma parameter dependence
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DOI：
10.1063/1.1652060
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发表时间：
2004-04
影响因子：
2.2
通讯作者：
N. Shimada;M. Hoshino
中科院分区：
文献类型：
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作者：
N. Shimada;M. Hoshino
除了众所周知的等离子体参数马赫数(MA)和等离子体β外，电子等离子体与回转频率之比的另一个等离子体参数ωPe/ΩCe(∝n/B)被强调为激波过渡区等离子体加热/加速过程的另一个重要参数。由于等离子体不稳定性，离子体流通过场活动转化为高能电子的过程不能仅用MA和β这样的宏观平均参数来描述。等离子体不稳定性的演化很大程度上取决于背景等离子体的性质，即磁场B和密度n，用ωPe/ΩCe表示。最近的研究表明，由于反射离子和入射电子之间的Buneman不稳定性的非线性演化而产生的电子相空间空穴在激波过渡区的粒子能量中起着重要的作用。然而，即使在相同的马赫数和等离子体β条件下，电子相空间空穴的形成也会受到抑制。
In addition to the well-known plasma parameters of Mach number (MA) and plasma β, the other plasma parameter of the frequency ratio of the electron plasma to gyration, ωpe/Ωce (∝n/B), is emphasized as another important parameter for the plasma heating/acceleration process in the shock transition region. The process of energy conversion from the ion bulk flow into energetic electrons through field activity due to plasma instabilities cannot be described only by such macro averaged parameters as MA and β. The evolution of plasma instabilities largely depends on the background plasma properties, i.e., magnetic field B and density n, which is represented by ωpe/Ωce. Recent studies have shown that electron phase space hole generation due to the nonlinear evolution of Buneman instability between reflected ions and inflow electrons plays an important role in particle energization in the shock transition region. However, even under the same Mach number and plasma β, the formation of electron phase space holes dep...