Ion distribution function and momentum transfer in the presence of an electrostatic pump wave in a magnetized plasma

The time evolution of the ion distribution function (IDF) when an electrostatic pump
wave is applied, with a frequency in the range of the low-order ion cyclotron
harmonics, is investigated by numerically integrating the Vlasov-Poisson system of
equations. The case of the wave propagation perpendicular to the external magnetic
field is considered. Previous extended analysis [1,2], with a reduced ion mass, have
shown the appearance of a regular periodic structure of the IDF, in the velocity plane
normal to the magnetic field, which seems to be caused by the periodic
"accumulation" of detrapped ions, leaving the trapping region.
In this paper, the numerical analysis is extended to the case of ions with their actual
mass, and the resulting moments of the IDF are computed and discussed.