Fokker-Planck calculations for JET ICRF heating scenarios

Abstract

Flux-averaged ICRF heating of the JET tokamak is considered, utilizing an anisotropic, time-dependent Fokker-Planck code. Alternative ICRF heating scenarios are considered, and fundamental minority deuterium and second-harmonic tritium and deuterium cases are selected for detailed analysis of wave accessibility, strong single-pass damping and enhanced ion-tail-produced fusions. It is found that enhanced fusions, resulting from heated minority deuterium ion tails, and second-harmonic deuterium heating, yielding fusion power gains near Q = 1, can be achieved near the plasma core with moderate absorbed power levels, pulse widths and energy confinement times. The corresponding case for second-harmonic tritium heating located on the major axis, with the associated fusion power gain, does not appear as attractive.