Plasma-wave interaction in helicon plasmas near the lower hybrid frequency

IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/1674-1056/ac40fdWe study the characteristics of plasma-wave interaction in helicon plasmas near the lower hybrid frequency. The (0D) dispersion relation is derived to analyze the properties of the wave propagation and a 1D cylindrical plasma-wave interaction model is established to investigate the power deposition and to implement the parametric analysis. It is concluded that the lower hybrid resonance is the main mechanism of the power deposition in helicon plasmas when the RF frequency is near the lower hybrid frequency and the power deposition mainly concentrates on a very thin layer near the boundary. Therefore, it causes that the plasma resistance has a large local peak near the lower hybrid frequency and the variation of the plasma density and the parallel wavenumber lead to the frequency shifting of the local peaks. It is found that the magnetic field is still proportional to the plasma density for the local maximum plasma resistance and the slope changes due to the transition.Project supported by the Open Fund for Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics (Grant No. ZWK1703). The authors also acknowledge the support of the National Natural Science Foundation of China (Grant No. 51907039) and Shenzhen Technology Project (Grant Nos. JCYJ20190806142603534 and ZDSYS201707280904031). The contribution of E. Ahedo and M. Merino has been supported by the ESPEOS project (Grant No. PID2019-108034RB-I00/AEI/10.13039/501100011033), funded by the Agencia Estatal de Investigacion (Spanish National Research Agency)