Numerical Simulation Study on Parameter Control of Helicon Wave Plasma Discharge Based on Three‐Dimensional Model

Helicon wave plasma discharge (HWPD) features low operating pressure, high plasma density and superior ionization efficiency, rendering it great application potential in plasma propulsion, thin‐film deposition and fundamental plasma physics research. The High Magnetic field Helicon eXperiment (HMHX) device adopts an asymmetric Shoji antenna, yet conventional one‐dimensional (1D) and two‐dimensional (2D) numerical models fail to fully reproduce the three‐dimensional (3D) spatiotemporal evolution of plasma inside the device, and cannot accurately resolve plasma transport and energy coupling mechanisms within the diffusion‐region. In this work, a simplified 3D multi‐physics model is established to investigate the axial and radial distributions of electron density, electron temperature, plasma potential and electron‐heavy‐particle collisional power loss under the modulation of three core control parameters: radio frequency (RF) power, external magnetic field intensity and background gas pressure. The physical mechanism governing the mode transition from inductively coupled plasma (ICP) to helicon wave plasma (HWP) under parametric tuning is elaborated. Simulation results indicate that moderately elevating RF power and magnetic field strength enable efficient excitation of Helicon wave modes; nevertheless, excessive values of both parameters trigger uneven spatial plasma distribution and degraded discharge stability. Increasing background pressure suppresses ionization reactions, lowering plasma density and overall discharge performance. All three control parameters modulate radial plasma gradients, forming a characteristic “blue core” discharge structure with high central density and elevated edge electron temperature. The 3D simulation framework and parametric evolution laws proposed in this study provide solid theoretical guidance for optimizing the operating conditions of HMHX.