Spacecraft orbiting Jupiter and performing flybys or landing on Jovian moons, such as Europa, experience an environment with high radiation levels. A Radiation Induced Outgassing Test (RIOT) campaign was initiated to study of radiation effects on contamination products evolving from spacecraft materials. Materials were irradiated with a flux of 2.6×1010 electrons/cm2/s at an energy of 1.5 MeV. Preliminary results from the ongoing test campaign include determining species produced by radiation scissioning of silicones, as well as measuring outgassing rates from the material. A physics based outgassing model has been developed to explain the observed experimental results. Material outgassing rates measured during, and subsequent to radiation exposure, can be modeled using a simple diffusion model. Use of Fick's law with a source term during irradiation, and without a source term when the radiation is turned off, can explain some of the experimental results. However, not all of the experimental results can be explained by this model. The observed discrepancies can be due to a combination of radiation interference with the test instrumentation and also due to radiation interaction with the test sample surface. Although additional work is needed, the experimental results can provide a basis for extrapolating experimentally measured outgassing rates to predict contamination outgassing as a function of the radiation levels encountered during a mission at Jupiter.
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