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arXiv 1508.01992physics.plasm-ph
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场电离等离子体中随机加热引起的电子剩余能量

Electron residual energy due to stochastic heating in field-ionized plasma

Elnaz Khalilzadeh, Jam Yazdanpanah, Jafar Jahanpanah, Amir Chakhmachi, Elnaz Yazdani

摘要:

本文研究了欠密场电离等离子体中由随机加热引起的电子剩余能量。首先利用两个反向传播的电磁波的概念模拟了等离子体的光学响应。对单个电子运动方程的求解表明,考虑电离后,可以得到比不考虑电离时具有更高剩余能量的电子。与运动的混沌性质相一致,发现对初始条件施加微小的改变,电子剩余能量将显著改变。为了解决完整的等离子体反应,已经进行了广泛的动力学1D-3V粒子模拟(PIC)。以这种方式,通过改变脉冲长度观察到两种不同的等离子体行为。结果表明,在足够长的脉冲长度的散射场的振幅足够高,作为第二个反向传播波触发的随机电子运动。另一方面,强度谱的分析表明,随着脉冲长度的增加,主要的散射机制更倾向于汤姆逊散射而不是拉曼散射。一个协变的形式主义是用来描述等离子体加热,使我们能够测量脉冲区域内的电子温度。

英文摘要:

The electron residual energy originated from the stochastic heating in under-dense field-ionized plasma is here investigated. The optical response of plasma is initially modeled by using the concept of two counter-propagating electromagnetic waves. The solution of motion equation of a single electron indicates that by including the ionization, the electron with higher residual energy compared to the case without ionization could be obtained. In agreement with chaotic nature of the motion, it is found that the electron residual energy will significantly be changed by applying a minor change to the initial conditions. Extensive kinetic 1D-3V particle-in-cell (PIC) simulations have been performed in order to resolve full plasma reactions. In this way, two different regimes of plasma behavior are observed by varying the pulse length. The results indicate that the amplitude of scattered fields in sufficient long pulse length is high enough to act as a second counter-propagating wave for triggering the stochastic electron motion. On the other hand, the analyses of intensity spectrum reveal this fact that the dominant scattering mechanism tends to Thomson rather Raman scattering by increasing the pulse length. A covariant formalism is used to describe the plasma heating so that it enables us to measure electron temperature inside the pulse region.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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