Impact of secondary and backscattered electron currents on absolute charging of structures used in spacecraft

Abstract

This article analyzes absolute charging of a metallic pyramid in single Maxwellian normal and worst cases of plasma environment. Capacitance of a pyramid for estimation of body potential is computed by the Method of Moments. Body potential temporal variation is obtained by numerically integrating the differential equation using the fourth order Runge‐Kutta method. Owing to a well‐known fact that diverse secondary and backscattered electron yields for different materials is the prime reason for most destructive differential charging, this work includes impact of normal and isotropic incidence of particles for a metal surface of aluminum. The decisive inferences related to these properties together with temporal variation of body potential are compared. Our computational results reveal a significant difference in the estimation of absolute charging in comparison with the same reported earlier.

A comparative study of body potential transient profile of geosynchronous orbit spacecraft in single and double Maxwellian plasma models

“…Absolute charging analysis of spacecraft reported in the previous studies of References [6,7] is confined to the effect of electron and ion current densities only, without considering SEY‐BEY. The analysis with the inclusion of SEY formulation of 18 has been discussed in Reference [19]. Since appropriate plasma model and precise SEY computation of different materials are decisive to charging analysis, we further extend the analysis for single and double Maxwellian plasma model with the widely used formulations of SEY 20,21 for the following three cases; (1) presence of currents due to SEY‐BEY at particle energy of 10 keV, and subsequently, (2) particle energy related to SEY‐BEY currents is varied from 0 to 50 keV for normal and isotropic incidence to examinethe resulting variations in absolute charging, and (3) computation of the range of absolute charging during normal and worst cases of plasma environment for the spacecraft structure of carbon fiber and aluminum.…”

“…Finally, comparing Equations ( 15) and ( 18), it can be shown that the sum of the elements of each sub-matrix is evaluated as an element of the capacitance matrix appearing in Equation (18). The expression for capacitance matrices are given by,…”

“…The analysis also excludes the impact of the recommended cases of single and double Maxwellian plasma environment on absolute charging. Absolute charging of a pyramid with the cuboid and an isolated pyramid (the modules of a spacecraft structure) is estimated in the presence of SEY-BEY in Reference [18]. In this work, SEY is considered according to the Reference [19].…”

Strategies for Determining Electron Yield Material Parameters for Spacecraft Charge Modeling

“…A cursory, investigation of recent studies returned a substantial list of references, which assumed that the NASCAP default values for Al were appropriate for their modeling, including Davis et al (2017), Marchand and Lira (2017), Wang et al (2017), Hughes and Schaub (2018), Schmidl et al (2018), Wolfley (2018), Bengtson et al (2019), andPandya et al (2019). It is significant to note that this ambiguity for Al has also been propagated by other international charging codes, including MUSCAT (Nakamura et al, 2018) and European Space Agency (2018).…”