Fast wave heating at intermediate ion cyclotron harmonics on the JIPP T-IIU tokamak

Abstract

Fast wave absorption and heating at a relatively high ion cyclotron harmonic (ω ≃ΩD) were studied on JIPP T-IIU. In spite of the low absorption efficiency predicted by a simple theory for present experimental parameters, appreciable electron and ion heating was observed. Heating is most effective at relatively low densities (n̄e ≃ 1 × 1019 m−3). An ion tail on the majority deuterium energy spectrum was observed, but not an ion tail on the minority hydrogen spectrum, which suggests the possibility of direct absorption of mode converted ion Bernstein wave power by deuterium ions.