Comparative study of surface modification and D retention between beryllium and beryllides under high flux plasma exposure

The microstructures and deuterium (D) retention properties were investigated for beryllium intermetallic compounds (beryllides), such as Be12Ti and Be12V, compared to pure beryllium (Be), exposed to high density pure D and helium (He) mixed plasmas. TEM cross-sectional observations revealed the formation of cone structures on the Be surface exposed to the plasmas at a moderate temperature of 573 K. The crystal structure of the cones and the mass loss caused by the plasma exposure implied that the cone structures were generated by sputtering. The Ti or V surface enrichment was observed on both beryllides with no cone structures developed. TDS measurements indicated that He seeding to D plasma caused a similar to 4 times reduction of the D retention for both beryllides, while no reduction was observed for Be. As a result, the beryllide samples exposed to D + He mixture plasmas showed a lower total D retention than in Be.

Automated summary

The investigation compared the microstructures and deuterium retention properties of beryllium intermetallic compounds (beryllides) with pure beryllium exposed to high density pure deuterium and helium mixed plasmas. The results showed that beryllides demonstrated a reduction in deuterium retention when seeded with helium, while pure beryllium did not show a significant reduction in deuterium retention. The cone structures observed on beryllium surfaces exposed to plasmas were found to be generated by sputtering.