Inclusion of trap creation model for non-linear charge trapping in highly insulating materials for spacecraft applications
Mentor:Alec Sim, Assistant Professor of Physics, Irvine Valley College
This work discusses an extension made to a theoretical model for charge transport in highly disordered insulating materials (HDIM) developed by the Utah State University Material Physics Group with applications to spacecraft charging. A modification is made to an expression describing the time dependent density of trapped charges within insulating materials to include the effects of trap creation via high electric field and ionization processes. The initial expression for trapped charge density is obtained from an approximation of the one dimensional trapping continuity equation where thermal excitation is taken to be negligible. In this form, the increase in trapped charge density is proportional to the injected charge flux and available trap density, namely the difference between density of trap states and occupied trap states. Via the introduction of a term for the total number of created traps as a function of time our new model can account for effects of trap creation and subsequent trapping of mobile charges within a HDIM. This new model will allow for the prediction of electrostatic discharge events in spacecraft applications due to high incident flux and applied fields -often found in typical spacecraft orbits- thus providing a new engineering tool in the mitigation of mission ending ESD phenomena.