Kiel 2011 – wissenschaftliches Programm
P 1.3: Vortrag
Montag, 28. März 2011, 17:10–17:25, HS H
Mass resolved ion densities in a hydrogen rare gas inductively coupled plasma — •Maik Sode, Thomas Schwarz-Selinger, Wolfgang Jacob, and Ursel Fantz — Max Planck Institut für Plasmaphysik, 85748 Garching, EURATOM Assoziation
Ion densities are quantified for plasmas in pure hydrogen and mixtures of hydrogen with helium, neon or argon by an energy dispersive mass spectrometer and a Langmuir probe. The plasma is generated inductively at a radio frequency of 13.56 MHz by a planar coil. Standard plasma conditions are p = 1.0 Pa and rf power 100 - 500 W. For pure H2 plasmas the dominant ion is H3+. For admixture with helium and neon H3+ remains the dominant ion up to 60 % admixed rare gas. For higher fractions the noble gas ion becomes dominant. In contrast, in hydrogen argon plasmas the argon hydrogen molecular ion ArH+ is the most dominant ion species in a wide parameter space. For the Ar/H2 case the experimental data are compared to results from a rate equation model describing the reactions in the plasma and losses to the wall. The following experimental data were used as additional input for the model: Te, ne, from Langmuir probe measurements and the H/H2 ratio and the gas temperature estimated by optical emission spectroscopy.