Interaction of Hydrogen Plasma With SiC/SiC Composite

Tritium permeation, particularly plasma driven permeation (PDP) through plasma facing materials has been identified as a critical safety issue for future fusion power devices. While PDP through metals has been reported earlier, this work presents the first measurements of permeation rates through SiC/SiC composite samples exposed to a modified RF-discharge plasma device. The response of the SiC/SiC composite samples to impinging plasma radiation was also investigated using SEM. In contrast to metals, SiC/SiC composite showed no evidence of PDP of deuterium. The SEMs revealed attack only of directly exposed fibers and fiber-matrix interfaces. In lieu of these measurements, SiC/SiC composites offer promising characteristics as plasma facing materials for future fusion devices.