LEAD螺旋波射频等离子体电子能量分布函数的测量

Electron energy distribution function measurements in LEAD helicon plasma

通过电压扫描探针测量了LEAD装置螺旋波射频等离子体伏安特性曲线和电子能量分布函数,并对等离子体基本参数剖面如电子温度、密度、等离子体电位和鞘电位降系数等进行了计算。实验发现在LEAD装置半径5cm以内的位置电子能量分布函数都遵循麦克斯韦分布。而在半径7cm附近,即与射频源线圈处于相同径向位置,电子能量呈现出典型的双麦克斯韦分布特征,这将导致传统探针基于麦克斯韦分布假设的诊断结果需要修正。

The voltage-current characteristics and electron energy distribution function(EEDF)of helicon plasma measured by a voltage swept probe in Linear Experimental Advanced Device(LEAD)are presented.The profiles of some basic plasma parameters,such as electron temperature,density,plasma potential and sheath potential coefficient are given.It is shown that the EEDFs within a radius of 5 cm conform to Maxwell distribution.However,the EEDF at the radius of 7 cm which is the same as that of the RF antenna has a bi-Maxwellian distribution.This will affect some traditional measurements based on Maxwellian EEDF.