Comparison of cold-fluid model and kinetic model in ICRH simulations

Ion cyclotron resonance heating (ICRH) is extensively used in magnetic confinement fusion, electric propulsion, and plasma–material interaction studies, while improving wave–plasma energy conversion efficiency remains challenging. Current ICRH simulations primarily rely on two approaches: the fast approximate cold-fluid models and the costly accurate kinetic models. The efficiency–accuracy dilemma poses a significant challenge for long-timescale self-consistent ICRH simulations. This study provides a systematic comparison between fluid and kinetic approaches in ICRH wave–plasma interactions simulating, based on linear plasma devices, aiming to provide a reference for model selection based on plasma parameters and operational regimes. A controllable method for determining the temperature threshold is proposed, beyond which kinetic models must be employed to simulate the ICRH process. Since collisionless damping becomes significant near the fundamental ion cyclotron resonance frequency, cyclotron effects must be explicitly included in simulations. Therefore, accurate power deposition requires the application of kinetic models or alternative simplified calculations based on first principles. However, below the temperature threshold, fluid-model field solvers can be utilized for rapid simulation of ICRH, while combined with the particle-in-cell method for the resonance heating process.