Pulsed X-Ray Exposures and Modeling for Tungsten as an IFE First Wall Material

Abstract

Dry-wall inertial fusion energy (IFE) power plants must survive repeated exposure to target threats that include x-rays, ions, and neutrons. While this exposure may lead to sputtering, exfoliation, transmutation, and swelling, more basic effects are thermomechanical in nature. In the present work, we use the newly developed RadHeat code to predict time-temperature profiles in a tungsten armor, which has been proposed for use in an IFE power plant. The XAPPER x-ray damage experiment is used to simulate thermal effects by operating at fluences that produce similar peak temperatures, temperature gradients, or thermomechanical stresses. Soft x-ray fluences in excess of 1 J/cm² are possible. Using RadHeat, we determine the XAPPER x-ray fluence needed to match expected peak surface temperatures. Such calculations are the first step in predicting the thermomechanical effects that are expected in an IFE system. Here, we report our findings and detail directions for future experiments and modeling.