Modulation of ion beams in two-component plasmas: Three-dimensional particle-in-cell simulation

The propagation of low energy continuous ion beams through background plasmas is studied numerically using a three-dimensional particle-in-cell code. It is found that after the well known self-modulation effect, a secondary self-modulation occurs, leading to a trimodal energy spectrum of the ion beam. The accuracy of the "focusing regions" concept is studied by comparing the phase relation of the wakefield and beam density. Furthermore, the form of the wakefield induced by two counter-propagation ion beams is verified.