固体润滑国家重点实验室（LSL）知识库

Sputtering properties of F82H and CLF-1 RAFM (reduced activation ferritic/martensitic) steels are investi- gated under exposure to high-flux He plasmas ( Γ_i ∼2–4 ×10 ²² m ⁻² s ⁻¹ ) in PISCES-B with a low incident ion energy of ∼80 eV and sample temperature, T_s , ranging from ∼573 K to 1053 K. Both steels are pri- marily alloys of Fe, Cr, and W. While sputtered W atoms were not detected during the exposure, sput- tered Fe and Cr atomic fluxes were spectroscopically quantified using S/XB values of Fe I and Cr I emis- sion lines, which were experimentally determined in this study. Sputtering yields of F82H obtained from spectroscopy agree well with those from mass loss measurements. The He ⁺ fluence-integrated sputtering yield of F82H and CLF-1 does not depend on T_s in the range of ∼573–873 K, but starts to increase at T_s ∼900 K. Sputtered Fe and Cr atomic fluxes are found to drop during the plasma exposure. The reduction of sputtering yield is explained by surface enrichment of W and development of surface morphology. The surface enrichment of W was measured with Auger electron spectroscopy, and is due to the observed preferential sputtering of Fe and Cr. Cone-like structures were observed with a scanning electron micro- scope, which become larger with increasing T s , and W fuzz is formed on top of the cones at T_s ≥973 K.