Review on helium behaviors in nanochannel tungsten film

Tungsten (W) as plasma facing material (PFM) needs to face an unprecedented harsh environment in the fusion reactor, which puts forward high requirements for its radiation tolerance. Among the many challenges, the rapid accumulation of helium (He) atoms to form numerous bubbles or even “fuzzy” nanostructure leads to swelling and embrittlement of W matrix and seriously shorten its service life, which is one of the most serious problems faced by PFM-W at present. In this review, we summarize the recent works on the nanochannel W films with high surface-to-volume ratio deposited by magnetron sputtering, and the behaviors of He in the nanochannel W films at different fusion-related irradiation environment. Experimental and simulation results showed that the nanochannel W films have better radiation tolerance performance in managing He behaviors than that of commercial bulk W.