Full-Wave Modeling of Electron Cyclotron Plasma Heating at the Fundamental and Second Harmonics for the GDMT Facility

Possible scenarios of auxiliary electron cyclotron plasma heating in various configurations of the next-generation open magnetic trap GDMT (Gas Dynamic Multiple Mirror trap) designed in Budker Institute of Nuclear Physics are considered. For this purpose, a full-wave impedance approach is used to model the interaction of electromagnetic waves with hot plasma, which allows one to consider the interaction of electromagnetic and quasi-electrostatic modes in the vicinity of the electron cyclotron resonance in an axisymmetric magnetic configuration. Heating scenarios using the ordinary electromagnetic mode at the fundamental harmonic and the extraordinary mode at the second harmonic are considered. For each case, the ranges of the setup parameters are determined in which a considered heating scheme can be effective; the optimal focusing of the quasi-optical microwave beam for heating efficiency is analyzed.