Parametric Study of Helicon Wave Current Drive in NCST
摘要
Helicon waves (HW) are fast magnetosonic waves that can efficiently drive off-axis plasma current in tokamak plasmas through electron Landau damping (ELD) and transit-time magnetic pumping (TTMP) effect. Simulation of helicon wave current drive (HCD) were conducted for the purpose of increasing the discharge current of the NCST, combined with theoretical analysis of wave absorption based on the dispersion relation. Key findings are as follows: (1) When the wave frequency f > 40 MHz, ELD becomes the dominant absorption mechanism for HW in NCST, which is confirmed by the significant increase in the Landau damping term with frequency (Fig. 1). (2) At a frequency of approximately 65 MHz, HCD effectively supplements the bootstrap current for the NCST scenario. (3) Under the optimal parameter combination (