Numerical simulation of an Inductively coupled plasma for electron beam generation by COMSOL Multiphysics

Abstract

A planar inductively coupled plasma discharge with a relatively independent electrostatic field inside is designed, and with the aid of a simulation model the ion flux and electron flux above the electron accelerated zone are studied. The diffusion electron flux mainly depends on the diffusion due to the electron density gradient and the migration in the ambipolar potential. Generally, the electron flux in plasma is much smaller than the electron flux calculated by the thermal velocity of the electrons. But in this research, above the electron accelerated zone the significantly larger electron density gradient results in the diffusion electron flux even much larger than that calculated by the electron thermal velocity. Because the direction of the diffusions due to the electron density gradient and the direction of the electron moving in the ambipolar potential are opposite, the distribution of the electron diffusion flux depends on the difference of them rather than the distributions of the electron density or electron temperature. With the increasing power, the electron flux also increases and the nonuniformity of them increases less than 1%.