On the preferential acceleration and heating of solar wind heavy ions

It is pointed out that the properties of solar wind ions heavier than H(+) have presented a puzzle to theorists for some time. The most recent theoretical efforts to explain the observations are considered, taking into account studies conducted by Dusenbery and Hollweg (1981) and Marsch et al. (1982). The first model of a wave-driven, three-fluid, supersonic solar wind is considered. Details of the resonant wave-particle interaction are discussed and the relevant equations for the model are derived. An investigation is conducted of the effects of resonant cyclotron acceleration and heating by a spectrum of nondispersive ion cyclotron waves on the model. It is found that there are serious difficulties with the hypothesis that the resonant cyclotron interaction is responsible for the preferential heating and acceleration of heavy ions in the solar wind. The model presented here is unable to produce the required energization by this mechanism. However, this model should be viewed as an approximate one, subject to possible correction by more advanced calculations.