Performing hydrogen permeation experiments for fusion applications
Permeation of hydrogen isotopes, especially tritium, is expected to be a major challenge for future fusion reactors due to the high temperatures expected. Countless permeation experiments have been performed with the aim to study hydrogen permeation and permeation barriers, varying in many ways: the materials used, the experimental conditions under which these materials are tested, and the detection methods that are employed. This talk will consider the main outcomes of these past investigations, categorising them by their mode of operation rather than by the materials studied. The limitations of scientific experiments in recreating future conditions in fusion fuel cycles, and efforts to decrease this discrepancy, are discussed. Aspects to consider when designing a permeation experiment and how these decisions affect the measurements that can be obtained are considered. I will conclude with recommendations on how future experimental investigations can maximise their contribution to studying hydrogen permeation through metals at fusion-relevant conditions.