Engineering Tool for Temperature, Electric Field and Dose Rate Dependence of High Resistivity Spacecraft Materials
An engineering tool has been developed to predict the equilibrium conductivity of common spacecraft insulating materials as a function of electric field, temperature, and adsorbed dose rate based on parameterized, analytic functions derived from physics-based theories. The USU Resistivity Calculator Engineering Tool calculates the total conductivity as the sum of three independent conductivity mechanisms: a thermally activated hopping conductivity, a variable range hopping conductivity, and a radiation induced conductivity using a total of nine independent fitting parameters determined from fits to an extensive data set taken by the Utah State University Materials Physics Group. It also provides a fit for the temperature dependence of the electrostatic breakdown field strength, in terms of a tenth independent fitting parameter related to an interchain bond strength. The extent of F, T and Ḋ measured in the experiments were designed to cover as much of the ranges typically encountered in space environments as possible. This Mathcad worksheet calculates the total conductivity and the individual contributions from each conductivity mechanism based on user inputs for F, T and Ḋ. It also plots 2D and 3D graphs of the conductivities over the appropriate full ranges of F, T and Ḋ.
JR Dennison, Alec Sim, Jerilyn Brunson, Steven Hart, Jodie Gillespie, Justin Dekany, Charles Sim and Dan Arnfield,“Engineering Tool for Temperature, Electric Field and Dose Rate Dependence of High Resistivity Spacecraft MaterialsPaper Number,” AIAA-2009-0562, Proceedings of the 47th American Institute of Aeronautics and Astronomics Meetingon Aerospace Sciences, 2009