The effect of the introduction of small amount of H2 on Ar-plasma properties

Abstract

The impact of the introduction of small amounts (up to 3.6 %) of H2 in Ar plasmas produced by a surfatron was studied. This was done in view of futures plans to measure the electron density via Hβ-broadening. The H2 concentration was varied between 1.2 and 3.6 % while the pressure was in range from 5 to 20 mbar. While changing the H2 concentration we studied the length of the plasma, the plasma wall heating and the electron temperature. The latter was measured using the method introduced in a previous study based on a combination of absolute line intensity measurements and a collisional radiative model. It was found that, for the mixture ratios we used, the electron temperature does not change but that the H2-addition has a substantial impact on the gas temperature.