Analysis of ICRF second harmonic heating of tritium in a D-T fusion reactor

From the quasi-linear theory, an approximate analytical expression is deduced to evaluate the average absorbed power density of ICRF second harmonic heating, and the conditions valid for this approximation are presented. To analyze the second harmonic heating of tritium, the cold plasma approximation is adopted to calculate the dispersion relations, and the code FPPAC is used to solve the two-dimensional time-dependent Fokker-Planck equation. For a typical D-T fusion reactor, the time dependent evolution of core plasma temperature, the distribution function of tritium and the reactivity enhancement have been calculated. It is shown that the ICRF heating will induce significant non-Maxwellian ion distribution and hence the reactivity enhancement only when the core plasma temperature is not too high, and that there will be no significant reactivity enhancement when the temperature is raised above 10 keV