Presentation and validation of the internal charging risk forecast in the PAGER framework

Abstract

The Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation project (PAGER) aims to provide a framework for space weather and related effects forecasts. One of the innovative concepts is to plug, downstream of the environment prediction models, an automatized chain evaluating both surface and internal charging to forecast a charging risk evaluation for spacecraft on GEO and MEO orbits.The evaluation of the internal charging risk induced by electrons of the radiation belts with an energy above ∼0.5 MeV, is carried out throughout an innovating approach, combining different charging models, downstream the environmental ones. The space weather forecast is provided by a simulation of the radiation belt performed with VERB-3D. Downstream, the charging analysis is mainly performed using SPIS-IC, the internal charging branch of the open-source SPIS software (Spacecraft Plasma Interaction Software). SPIS-IC requires the prior computation of the source terms of space charge and dose rates resulting from the transport of primary electrons through the spacecraft structure. This is done beforehand using a 3D direct Monte-Carlo approach. In addition, a simple and fast internal charging 1D code, ICOne has been developed and is also used to evaluate the internal charging risk, based on a semi-empirical deposition rule.The internal charging modeling chain is used to carry out on one hand an evaluation of the electrical risk on a satellite in MEO orbit surrounded by an environment simulated by the VERB-3D Fokker-Plank code, and on the other hand, to reproduce measurements of a charging event of GIOVE-A.