Ion cyclotron resonance frequency heating of deuterium plasmas in the Joint European Torus: Modeling of the resonant minority ion distribution function
D. Testa et al., Ion cyclotron resonance frequency heating of deuterium plasmas in the Joint European Torus: Modeling of the resonant minority ion distribution function, PHYS PLASMA, 6(9), 1999, pp. 3489-3497
Experiments were carried out in JET, the Joint European Torus [J. Wesson, T
okamaks (Clarendon, Oxford, 1997), pp. 581-603], to heat deuterium plasmas
using ion cyclotron resonance frequency (ICRF) heating at fundamental hydro
gen and second harmonic deuterium frequencies. These plasmas contained two
minority resonant ion species, protons, and nonthermal deuterons due to neu
tral beam injection (NBI). To determine the resonant ion energy distributio
n functions in such plasmas, an iterative method for solving the hot-plasma
dispersion relation was developed using a complex perpendicular wave numbe
r in cylindrical geometry. The distribution function of ICRF-heated ions is
strongly anisotropic and significantly hotter than that of nonresonating p
articles. Therefore thermal and overlapping cyclotron harmonics effects wer
e considered in computing wave dispersion and absorption. The formal soluti
on of the lowest-order Fokker-Planck equation is derived for the slowing-do
wn NBI deuterons. In a companion paper these results are applied to interpr
etation of measurements of distribution functions of ICRF-heated ions in th
e JET. [S1070-664X(99)00209-8].