Analytical model of hydrogen inventory saturation in the subsurface of the wall material and comparison to Reaction-Diffusion simulations

We herein introduce an analytical model of hydrogen inventory saturation in the subsurface materials (several micrometers depth) under plasma implantation. This is valid for which desorption process not limited by recombination at surface. It based on a simplified assumption implantation both ions and atoms (point sources) stationary approach. The provides approximation density profile mobile/interstitial trapped defects layer. shows good agreement with Reaction-Diffusion simulations deuterium tungsten different material temperatures. For fusion relevant beryllium, it shown that most found traps. gives filling ratio traps steady-state fstat,iBULK. simple parameter indicates how total builds up during exposure way to understand retention dynamics observed non-linear simulations.