In Situ Measurements of Electron-Beam-Induced Surface Voltage of Highly Resistive Materials

Abstract

Surface charging and subsequent electrostatic discharge due to interactions with the space environment is one of the primary concerns of spacecraft charging studies. Laboratory measurements of the evolution of surface voltages and dissipation currents under simulated space conditions are the primary method used to determine the response of key spacecraft materials to diverse incident fluxes. Increasing the database of information for the electronic properties of insulating materials can assist spacecraft designers in mitigating the harsh effects of the space environment. The Utah State Materials Physics Group, with the funding of the NASA James Webb Space Telescope project and personnel support from the United States Air Force PALACE Acquire program, has developed new instrumentation capable of noncontact measurements of the electron-beam-induced surface voltage as a function of time and position for nonconductive spacecraft materials. This new instrumentation used in conjunction with the capabilities of an existing ultrahigh vacuum electron emission test chamber facilitates measurements of charge accumulation, bulk resistivity, effects of charge accumulation and depletion on yield measurements, electron-induced electrostatic breakdown potentials, radiation-induced conductivity effects, and the radial dispersion of surface voltage. Modeling and understanding the complex relationships between the spacecraft and its surroundings are fundamentally based on detailed knowledge of how individual materials store and transport charge. The ability to better understand how these affect spacecraft materials will help make the complex spacecraft are exploring the edges of the universe more stable, reliable, and economic