On equations for ion cyclotron modes in ‘warm’ bounded plasmas

Abstract

An equation describing eigenmodes in the ion cyclotron frequency range in ‘warm’ bounded plasmas, i.e. eigenmodes which are absent in the two-fluid model but exist in kinetic theory due to finite Larmor radius of the ions, is derived for the first time. It is valid for electrostatic modes but the developed approach is generic. Calculations are carried out for two cases: first, for a homogeneous magnetic field; second, taking into account the effects of toroidicity in tokamaks. It is found that, in general, equations for eigenmodes in warm plasmas do not reduce to second-order differential equations (in contrast to those which are usually used to describe the radial structure of eigenmodes in fusion devices). The study of modes in warm plasmas is of interest, in particular, in connection with the recent observations of superthermal ion cyclotron emission in the NSTX-U spherical torus and DIII-D tokamak, which can be hardly explained by conventional theories employing fast magnetoacoustic modes.

Phase matching of electromagnetic wave on moving interface

“…随着科学技术的发展，电磁波在运动物体表面的折射反射和内部的传播从技术应用层面 受到研究者广泛关注 [1][2][3][4][5][6][7] 。运动界面的电磁场边界条件作为其中一重要问题，导出方法主要有 二：其一是如文献 [8,9,11] 利用 Kinematic Integral Form 导出，但 Kinematic Integral Form 是 建立在经典时空观之下的；其二是如文献 [12][13][14] 从相对论变换出发导出。其中文献 [12,13] 从尺 缩效应和几何关系导出的，文献 [14] 从相对性原理出发导出的，但是前者导出的形式与利用 Kinematic Integral Form 导出的相同，后者却有所差异。 同时相位匹配作为一个基于电磁场连续性边界条件分析非均匀介质中电磁波传播的重要 方法 [15][16][17][18] ，只有文献 [8] 基于 Galileo 变换对运动边界有所讨论。文献 [13] 指出，运动边界对电 磁波传播的相对论效应是不能被忽略，文献 [8] [19,20]…”