Feasibility of rf plasma heating in the Globus-M spherical tokamak at frequencies above the ion cyclotron frequency

Feasibility of rf plasma heating in the Globus-M spherical tokamak at frequencies several times higher than the ion cyclotron frequency is considered. Results from a numerical analysis of this problem by using one-and two-dimensional codes are presented. It is shown that, for the plasma parameters attainable in this device, the single-pass absorption of fast magnetosonic waves reaches 60%. The energy is released near the plasma axis. The radiation resistance of a one-loop antenna should be close to 1 Ω. The design of an antenna that allows one to match the rf oscillator to the load is described. The parameters of the antenna resonator required for optimum operation of the antenna are given.