Nonequilibrium Hydrogen Plasmas in Microwave Fields by Two-Temperature Model

Hydrogen plasmas in microwave discharge at 1.0 atm are studied with the two-temperature model, and are compared with local thermodynamic equilibrium plasmas and with two-temperature plasmas of dc discharge. There are two kinds of stable states: one in a lower power region (region-I) and the other in a higher power region (region-II). The plasma in the region-I is the same as the glow plasma of dc discharge. In region-II, electron and gas temperatures at the axis decrease with increasing dissipated power per unit length, because the column radius increases owing to the skin effect. In the lower part of the region-II, the plasma is filamentary. The temperature profiles in the region agree with the results measured by Arata et al. In the higher part of the region-II, the electron temperature in the outer area is higher than that in the intermediate area.