Resonant power absorption in nonuniform toroidal helicon plasma sources

In this paper, we present numerical simulation results that indicate that under certain conditions, a double-saddle antenna can excite helicon modes that resonate with the driving frequency in a nonuniform toroidal plasma, and m = 1 and m = 2 resonant standing helicon waves can separate or coexist in the toroidal plasma. The power absorption associated with the resonant standing wave is much larger than the power absorption associated with the nonresonant eigenmodes and accounts for most of the RF power deposited into the plasma. By adjusting the antenna frequency and wavenumber kz, the wave field structure, such as the standing wave pattern, the partially travelling-partially standing wave structure and the standing wave structure with amplitude modulation, can be controlled, which means that one can possibly control the resonant power absorption through careful antenna geometry and frequency design.

Automated summary

This paper presents numerical simulation results showing that under certain conditions, a double-saddle antenna can excite helicon modes which resonate with the driving frequency in a nonuniform toroidal plasma. The resonant standing helicon waves can separate or coexist in the toroidal plasma. The power absorption of the resonant standing waves is much larger than the power absorption of nonresonant eigenmodes, and it accounts for most of the RF power deposited into the plasma.