On the velocity distributions of dust-related inner-source pickup ions

Abstract

We simulate velocity distributions for inner-source pickup ions in two scenarios for their origin. One scenario creates inner-source pickup ions by charge exchange and energy loss in very small (typically submicron-sized) dust grains (Wimmer-Schweingruber and Bochsler 2003), while the other liberates solar wind ions previously implanted in larger (typically 1 μm) dust grains (Geiss et al. 1995; and Gloeckler and Geiss 1998). The two scenarios differ by the initial velocity with which the pickup ions are created; the fine-dust model produces a wide initial velocity distribution, while the coarse-dust model releases them essentially at rest. We investigate the differences in the distributions once these ions have been transported out to an observer at 1 AU or beyond. Copyright 2006 by the American Geophysical Union.