Work

Analysis of parametric decay instabilities during helicon wave injection into tokamak plasma

Year: 2025

Type: article

Abstract: The parametric decay instability (PDI) during helicon wave injection into tokamak plasmas is investigated based on its local dispersion relation under typical scrape-off layer conditions. The helicon wave can decay into a lower hybrid wave as the sideband mode and usually the ion cyclotron quasi-mode and its harmonics as low-frequency modes, which shows qualitative consistency with the experimental results of DIII-D tokamak [Pinsker et al., Nucl. Fusion 64, 126058 (2024)]. The parameter dependence of the PDI is also analyzed. The instability can be suppressed by a higher electron temperature or a stronger magnetic field. In contrast, increasing in the plasma density enhances the local growth rate, suggesting that helicon waves may also encounter a density limit similar to that observed for lower hybrid waves.

Source: Physics of Plasmas

DOI: 10.1063/5.0290940

Authors: Xiaoyu Yang, Zhe Gao

Institution: Tsinghua University

Language: English

Topic: Magnetic confinement fusion research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: National Natural Science Foundation of China

Award: G3278332556