2D Full-Wave Simulation of the Propagation and Absorption of a Microwave Beam in the L-2M Stellarator Plasma

Abstract

A 2D full-wave-model is developed and a 2D numerical code is designed to calculate the propagation and absorption of an X-polarized microwave beam in magnetized plasma with allowance for the nonlocal (differential) thermal correction to the plasma permittivity tensor near the electron-cyclotron resonance (ECR) at the second harmonic of the electron gyrofrequency. 2D full-wave numerical simulations of the propagation and absorption of the heating microwave beam in the standard poloidal cross section of the L‑2M stellarator are performed for three ECR heating scenarios differing in the position of the resonance region: central heating, heating on the vacuum magnetic axis, and off-axis heating at the midradius of the plasma column. It is shown that optimal conditions for microwave power deposition in plasma are achieved when the microwave beam is incident normally on the resonance surface, which, in the offered 2D model, takes place under ECR heating on the vacuum magnetic axis.