电子密度是低温等离子体的重要参数之一,仅采用发射光谱或Langmuir探针一种诊断方法,很难测量出该参数及其分布。针对这一问题,提出了用Langmuir探针法标定的发射光谱法,用于诊断等离子体电子密度及其分布。通过对一定长度表面波等离子体源的实验测量,验证了该方法的可行性。对于电子温度变化不大的等离子体,利用本文提出的诊断方法,可以测量出其电子密度及其分布。提出的诊断方法为低温等离子体参数的实验诊断提供了一种新的途径。
A novel technique was developed to diagnose the electron density and its distribution in the low tempera- ture plasma with emission spectroscopy demarcated by Langmuir probe. Theoretically speaking,for a weakly varying electron temperature,the plasma emission intensity could be approximated to depend linearly on the electron density, which can be diagnosed with Langmuir probe. Sine the spatial distribution of the plasma emission intensity can also be measured, the linear dependence of the electron density on the emission intensity can be derived by data processing. In the case of the surface wave plasma source, the linear dependence of the electron density on the emission intensity was evaluated in the newly-developed technique. The calculated and measured results of the electron density and its spatial distribution were found to be in fairly good agreement. We suggest that the new method be of some technological interest in diagnosis of other low temperature plasma.