Evaluating retention and erosion properties of SiC via high-flux plasma exposures*

Excellent thermal strength and low fuel permeability may make silicon carbide (SiC) a viable candidate for future plasma facing components (PFCs). While tungsten (W) exhibits favorable thermal and mechanical properties, high line radiation from eroded material may induce major disruptions. SiC is a promising low-Z alternative, but concerns regarding tritium accumulation due to retention and chemical sputtering under hydrogenic bombardment necessitate further experimentation. Fuel retention and surface erosion by high-flux, low-energy deuterium plasma implantation were investigated on the PISCES linear plasma device to complement concurrent DiMES exposures in DIII-D. Irradiations were performed at different surface temperatures, ion impact energies, and fluences on C, SiC, and W surfaces. Differences in methane production between C and SiC samples were tracked via in situ quadrupole mass spectrometry. Trap energies and desorption fluxes determined from post-mortem thermal desorption spectroscopy were used to assess the viability of SiC PFCs. Future exposures on functionally-graded W-SiC surfaces will explore potential benefits of mixed-material components.