The plasma produced by an electric discharge of helium with the pressure range 100~700 Pa in a closed cavity is diagnosed by this way at three frequencies of 6.2,6.8 and 7.4 GHz. As a comparison,the Langmuir double probe method is used at the same time.

• 使用该方法对100~700 Pa范围内氦气辉光放电等离子体进行了诊断；选择6.；2；6