Contribution of slow waves on production of high-density plasmas by m=0 helicon waves

Abstract

The contribution of the slow waves (SWs) on high-density plasma production by m=0 helicon waves is investigated in H2, D2, He, N2, Ne, Ar, and Xe plasmas. The density-jump is observed in all the gases used at optimum external magnetic fields B0. The measured plasma density np as a function of B0 peaks at a condition close to the lower-hybrid resonance in H2, D2, He, N2, and Ne, whereas, the measured dispersion relation indicates the excitation of helicon wave. Dispersion relation of electromagnetic waves is solved using dielectric tensor elements of a cold uniform plasma including ion terms, which shows two branches: the SW and fast (helicon) wave. The transition from the ionization by SWs, which are excited in the low-density plasma produced by an antenna induction field, to that by helicon waves has been predicted to explain the mechanism to produce the high-density plasma in the helicon wave discharges.