Analysis and Tests of a Satellite Model in a Photon Environment

An analysis and experimental program aimed at testing the predictive capability of tools used in SGEMP analyses of satellites has been completed. The program consisted of a PIMBS IA test exposure of a scale model of a representative satellite followed by analytical predictions of the responses using Lumped Element Modeling (LEM1,2,3,4) and the two-dimensional SGEMP code ABORC.5 This is a companion effort to one previously completed on a right circular cylinder using the same photon source. The PIMBS IA produces a fluence of the order of 10-5 cal/cm5 at the object with a pulse width at half maximum of 55 to 60 nsec. This is non-space-charge-limited, low-frequency regime which is a low-stress test of the tools as far as drive functions are concerned. Conversely, while the complexity of the object is not fully representative of real satellites, even it is beyond the capability of either tool to model exactly and so represents a high-stress test. The post test predictions, performed on a one pass basis, i.e., there was no attempt to iterate the model to improve agreement, produced structural currents ranging from a factor of 6 lower to a factor of 35 higher than than the corresponding measurements. The LEM also modeled the simple cables which were present in the test object and produced bulk currents ranging from a factor of 1.1 lower to a factor of 95 higher than the measurements.