物理学报2026，Vol.75Issue(9)：56-65,10.DOI:10.7498/aps.75.20260190
低磁场峰螺旋波等离子体的波传播和功率耦合特性
Wave propagation and power coupling characteristics of low-field peak helicon plasma
摘要
Abstract
Low-field peak(LFP)phenomena in helicon plasmas represent an important nonlinear feature of low-magnetic-field helicon discharges and are closely associated with wave propagation,reflection,and power coupling processes.Understanding the evolution of wave propagation characteristics under low magnetic field conditions is therefore essential for elucidating the physical mechanisms underlying LFP helicon plasmas.In this work,argon helicon plasmas excited by a single-loop antenna are systematically investigated through numerical simulations using the HELIC code,with a focus on wave propagation and power coupling characteristics in the low magnetic field regime.To quantitatively characterize the propagation state of helicon waves,a multi-parameter standing-wave analysis framework is introduced.This framework includes the standing wave ratio(SWR),spatial distributions of wave amplitude and phase,amplitude ratios of forward and reflected waves,amplitude and power reflection coefficients,load resistance evolution,radial power deposition,cumulative power distribution,and axial wavenumber power spectra.Based on these diagnostic parameters,the transition of wave propagation from a standing-wave-dominated regime to a traveling-wave-dominated regime is analyzed from the perspectives of spatial field structure,spectral characteristics,and power deposition.The numerical results show that under low magnetic field conditions,strong axial reflections lead to pronounced standing-wave structures,resulting in localized power deposition near the antenna region.As the background magnetic field increases,the reflection strength gradually diminishes,and the propagation state evolves into a traveling-wave-dominated regime.This transition is consistently characterized by a decrease in SWR and reflection coefficients,a reduction in phase discontinuities,and stabilization of the effective axial wavenumber.Meanwhile,the antenna-plasma coupling strength increases with magnetic field,as indicated by the rise in load resistance.The power deposition pattern also evolves with magnetic field,exhibiting a gradual shift of radial power deposition from the plasma edge toward the core region.In addition,the axial wavenumber power spectrum indicates that the absorbed power becomes increasingly concentrated at lower wavenumbers as the magnetic field increases.These results provide quantitative insights into wave propagation and power coupling processes in low-magnetic-field helicon discharges and offer useful references for future numerical studies and experimental diagnostics of LFP helicon plasmas.关键词
螺旋波等离子体/低磁场峰/驻波比Key words
helicon plasma/low-field peak/standing-wave ratio引用本文复制引用
罗苗健,苌磊,马婧婧,阚子晨,张世杰,赵应鑫..低磁场峰螺旋波等离子体的波传播和功率耦合特性[J].物理学报,2026,75(9):56-65,10.基金项目
国家自然科学基金(批准号:92271113,12411540222,12481540165)、重庆市自然科学基金(批准号:CSTB2025NSCQ-GPX0725)和新奥能源研究院氢硼聚变研究基金(批准号:2025ENNHB01-011)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.92271113,12411540222,12481540165),the Natural Science Foundation of Chongqing,China(Grant No.CSTB2025NSCQ-GPX0725),and the ENN Energy Research Institute Hydrogen-Boron Fusion Research Fund(Grant No.2025ENNHB01-011). （批准号:92271113,12411540222,12481540165）
