LAUSR

A hybrid model consisting of a one‐dimensional radio frequency sheath model and an equivalent circuit model is used to investigate the effect of the non‐Maxwellian plasma with enhanced electron tails on ion energy distribution (IED) at the plasma–wall interface. With the assumption that electrons obey the Kappa distribution in which the parameter κ characterizes the deviation from Maxwellian distribution, the bimodal shape of the IED can always be found with the decrease of κ under the condition of current experimental advanced superconducting tokamak (EAST) discharges during the ion cyclotron range of frequency wave heating. However, the height of the low‐energy peak of the IED decreases, while the high‐energy peak does not change significantly. In addition, the IED shifts towards the higher‐energy regime, and the width of the IED expands with the decrease of κ. It is also shown that frequency and amplitude of the disturbance current, bulk plasma density, and ion temperature are the crucial parameters for determining the shape of IED even in the presence of super‐thermal electrons.