H-retention in tungsten fibre-reinforced tungsten composites

Deuterium (D) retention in Wf/W manufactured by chemical vapor deposition (CVD) has been investigated using Wf/W single layered model systems consisting of a single plane of unidirectional tungsten fibers embedded in a tungsten matrix produced by CVD. Various parameters with potential influence on the D retention, such as the choice of an erbium oxide interface and potassium doping, have been included in the investigation. The samples have been ground to varying distances between surface and fiber plane - exposing distinct details of the Wf/W microstructures at the surface. After exposure to low temperature D plasma, the D retention of all samples was measured by nuclear reaction analysis (NRA) and thermal desorption spectroscopy (TDS). It was found that the D retention in Wf/W composites is higher than in reference samples made from hot-rolled W by factors between 2 and 5. In addition, a comparison of NRA and TDS data indicated that D penetrates faster into the depth of Wf/W material than into hot-rolled tungsten.