The problem of the radial diffusion of fast electrons in tokamak plasmas and its impact on electron cyclotron diagnostics is investigated. A three-dimensional Fokker-Planck code has been developed describing the evolution of the electron distribution function due to the action of Coulomb collisions, DC electric fields, RF heating and radial diffusion induced by turbulent magnetic fields. In ohmic plasmas, non-Maxwellian distributions are generated by the radial diffusion process in the pressure gradient region; it is shown that vertical electron cyclotron emission or transmission measurements on non-central chords yield, in principle, detailed information on the structure of the superthermal electron distribution. This effect can be used to investigate the radial structure and properties of the turbulent fields. In lower-hybrid current driven plasmas, the possibility of diagnosing fast electron diffusion by electron cyclotron emission (ECE) in the equatorial plane at large toroidal angles, and frequencies between the first and second harmonic is analysed and discussed.
托卡马克等离子体中快电子的径向扩散及其对电子回旋诊断的影响被研究。开发了一个三维福克-普朗克程序，用于描述由库仑碰撞、直流电场、射频加热以及湍流磁场引起的径向扩散共同作用下电子分布函数的演化。在欧姆等离子体中，非麦克斯韦分布由压力梯度区域中的径向扩散过程产生；研究表明，在非中心弦上的垂直电子回旋发射或透射测量原则上可以提供超热电子分布结构的详细信息。这一效应可用于研究湍流磁场的径向结构和性质。在低杂波驱动电流等离子体中，分析了在赤道面内、大环向角以及第一与第二谐波之间通过电子回旋发射诊断快电子扩散的可能性，并进行了讨论。