Ion wake fields in a plasma with negative ions.

Abstract

Ion wake fields in a quasineutral plasma that contains negative ions are theoretically examined using two independent approaches. The two analyses described here are based on the initial assumption that a driving ion bunch may be injected into either a drifting plasma or a stationary plasma. Both methods predict that the ion wake fields may be oscillatory, constant, or decrease exponentially. A formula for the period of the oscillation frequency of the ion wake field is derived. Effects of driving ion bunches with different characteristics on the wake field excitation and modulation are presented.