An Improved Electron Pre-Sheath Model for TSS-1R Current Enhancement Computations

Abstract

This report presents improvements of investigations on the Tethered Satellite System (TSS)-1R electron current enhancement due to magnetic limited collections. New analytical expressions are obtained for the potential and temperature changes across the pre-sheath. The mathematical treatments in this work are more rigorous than one past approach. More experimental measurements collected in the ionosphere during the TSS-1R mission are adopted for validations. The relations developed in this work offer two bounding curves for these data points quite successfully; the average of these two curves is close to the curve-fitting results for the measurements; and an average of 2.95 times larger than the Parker-Murphy theory is revealed. The results indicate that including the pre-sheath analysis is important to compute the electron current enhancement due to magnetic limitations.

A parallel particle-in-cell code for spacecraft charging problems

“…For drifting plasma flows, usually the measured or simulated currents can be several times larger than the theoretically predicted values. One example is the magnetic limited electron currents collected by the tethering cable during the TSS-1R experiment in space (Janeski, Scales & Hall 2014;Cooke & Katz 1998;Cai 2017). In figure 23(c), the Y-axis represents the simulation results, and the X-axis represents the theoretical values predicted by the Parker-Murphy theory.…”