The dispersion relation for D(3He) ion-cyclotron resonance heating

Abstract
The fourth‐order dispersion relation for D(3He) obtained from a straightforward small kρD expansion does not properly reproduce the exact kinetic dispersion relation near ion–ion hybrid resonance. It is shown that, in general, whenever the majority is not resonant the expanded dispersion relation may break down. A method to obtain a correct approximate fourth‐order dispersion relation has been developed.