Studies on the Distribution Function of Minority Ions Under ICRF Wave Heating

Abstract

A simple analytic expression for the two-dimensional minority ion distribution function generated by wave heating in the ion cyclotron range of frequencies (ICRF) is constructed from numerical solutions of the bounce-averaged quasilinear kinetic equation. Unlike the previous two-dimensional analytic solutions, this analytical representation is valid not only in the energetic tail region, but over most of the domain of velocity space of practical interest. The error of the representation in two-dimensional form is less than 40%, but most of the error being localized near upsilon(parallel-to)m) congruent-to 0 and much smaller elsewhere. The representation can provide a basis for a kinetic analysis of various confinements and stability of an ICRF wave heated plasma.