Nonlinear Ion Cyclotron Resonance in Electromagnetic Wave with Non-Uniform Amplitude

抄録

The cyclotron motion of ion in a nonuniform electromagnetic wave is analysed using the multiple-time-scale-expansion method. A set of nonlinear equations which describes the evolutions of the gyroradius ρ, the gyrophase β, and the average velocity ‹ v_z› along the magntic field B₀ is obtained. The set is found exactly integrable and three conservation relations are obtained for an arbitrary harmonic among ρ, β, ‹ v_z› and the drift coordinates perpendicular to B₀. The theory includes the one obtained for the fundamental harmonic and a uniform amplitude wave and is also applied to ion acceleration in a non-uniform field near an antenna used in an ion-cyclotron-range-of-frequencies (ICRF) wave heating. Thus the theory seems to be more rigorous and general than the previous ones.