Solar Array Plasma Interaction: Influence of Interconnect Shape on Primary Arc Parameters

Abstract

When immersed in a low Earth orbit-like plasma environment, including that generated by electric propulsion thrusters such as arcjets, Hall current thrusters, or ion thrusters, negatively biased solar cells are susceptible to arcing, typically initiated at triple point locations. The physical mechanisms for, and modeling of, primary (trigger) arc generation have been studied previously in detail by numerous authors and institutions. However, the particular influence of solar cell interconnector shape remains to be explored in a high level of quantitative detail at bias voltages achievable by typical Earth-orbiting spacecraft. The present study focuses on the specific influence of the strain-relief and Z-bend interconnector shapes on commonly characterized solar array arcing parameters of onset voltage and arc rate at representative bias voltages within realistic plasma environments. Results yielded quantitatively significant findings, indicating that specific designs are susceptible to arc inception at bias voltages readily achievable at near Earth orbits.