Analysis of thermal desorption spectra to understand the migration of hydrogen in tungsten

Tungsten and tungsten alloys are candidate plasma-facing materials for future fusion reactors due to their excellent thermal properties and sputtering characteristics. A Sandia National Laboratories experimental program investigated the retention and release characteristics of hydrogen isotopes in tungsten and tungsten doped with 1% lanthanum oxide. A single model based on a high recombination rate coefficient, enhanced diffusivity in the implant zone for high flux experiments, and a 1.4 eV trap was capable of simulating all of the data accumulated in the experimental program. In this report, the model is now applied to data obtained by other researchers examining hydrogen migration in tungsten. Almost without exception, the model was able to accurately duplicate the hydrogen isotope retention and release with the single variable of trap density.