Use of the multidimensional WKB method to describe propagation of lower hybrid waves in tokamak plasma
Use of the multidimensional WKB method to describe propagation of lower hybrid waves in tokamak plasma
复制标题
DOI：
10.1088/0029-5515/32/7/i01
复制
发表时间：
1992-07
期刊：
影响因子：
3.3
通讯作者：
G. Pereverzev
中科院分区：
文献类型：
--
作者：
G. Pereverzev
研究了衍射对低杂波在托卡马克等离子体中传播的影响。由于缺乏合适的方法来求解波动方程，这种影响还没有被研究过。一种渐近方法的开发，而使用的准经典描述的方向上的群速度，保留波描述垂直于该方向。这种方法把一般的波动方程化为一个常微分方程组。结果表明，考虑到LH光束的波动特性，将导致LH光束出现明显的衍射模糊。这种效应在构型空间和光谱空间中都有发生。在第一种情况下，它导致吸收功率分布的加宽。在第二种情况下，它用慢波丰富了光谱，增加了与电子的相互作用。衍射的影响大于通常考虑的几何光学的影响
The influence of diffraction on the propagation of lower hybrid (LH) waves in tokamak plasma was studied. This effect has not been investigated before owing to a lack of suitable methods for solving the wave equation. An asymptotic method is developed which, while using a quasi-classical description in the direction of the group velocity, retains a wave description perpendicular to that direction. This method reduces the general wave equation to a system of ordinary differential equations. It is shown that allowance for the wave properties results in significant diffractional blurring of LH wave beams. This effect occurs in both configurational space and spectral space. In the first, it causes broadening of the absorbed power profile. In the second, it enriches the spectrum with slow waves, increasing interaction with electrons. The effect of diffraction is greater than the effects of the geometrical optics usually taken into account