Transport of Hydrogen across Surfaces and Interfaces in TESSIM-X

The transport of hydrogen isotopes (His) through the first wall of fusion devices is the driving process for HIs retention but also for permeation to the coolant. Both of these processes have fundamental implications for the safety and the tritium self-sufficiency of a fusion reactor. The first wall of a future fusion reactor will be comprised of the top armor material W and structural materials below like steel or Cu alloys that connect the top plasma-facing surface to the coolant. Therefore, the transport through the whole component from the W armor layer to the coolant needs to be understood. The diffusion trapping code TESSIM-X is capable of handling multi material interfaces and features a fully kinetic surface model that implements the time dependent transport of HIs given an energy landscape. This presentation will describe the physics of HIs transition across solid/solid and solid /gas interfaces.