Abstract
Helicon plasma density may show a non-monotonic dependence on the magnetic field at low strength, so-called "low-field peak (LFP)."We presented the multiple LFPs and the formation mechanism in argon helicon plasmas in this paper. Propagating conditions of helicon (H) and Trivelpiece-Gould (TG) waves in collisional plasmas were calculated based on the dispersion relation. It is demonstrated that there are two mechanisms during mode transition responsible for LFP, i.e., resonance of H- and TG-waves and anti-resonance of TG-wave. Especially, H-TG resonance of the highest axial mode in the helicon plasma results in a density jump rather than a density peak due to the mode transition from non-wave to co-H/TG-wave mode. Higher plasma density in lower magnetic fields is helpful for achievement of multiple LFPs in argon helicon plasmas.
Original language | English |
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Article number | 093511 |
Journal | Physics of Plasmas |
Volume | 29 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 Sept 2022 |