Continued analysis of ion current collection in the plasma wake during the charging hazards and wake studies (CHAWS) experiment

Summary form only given, as follows. The charging hazards and wake studies experiments (CHAWS I and II) have returned a wealth of data on the interaction between the Wake Shield Facility (WSF) and LEO plasma. Previous work at M.I.T. using the limited amount of CHAWS I data developed a semi-analytical ´bubble´ model describing the high voltage (>300 V) current collection to the Langmuir probe in the wake of the WSF once the current contribution due to secondary electron emission (SEE) was removed. A newly calibrated version of this model is presented and its application to the more extensive CHAWS II wake-side data is demonstrated. Also included is a discussion of particle in cell (PIC) code prediction of secondary species (H+) involvement in the low voltage (<300 V) current collection and a possible semi-analytical description is suggested.