Pulsation Effects of Incident Ion Energy on W Fuzz Growth

Abstract

Fuzzy nanostructure growth occurs on tungsten (W) surfaces by the exposure to helium (He) plasmas. We investigated pulsation effect in the incident energy of He ions on W fuzz growth. It is shown that He irradiation contributes to the growth of fuzzy layer even if the incident ion energy was less than the threshold energy of 20 - 30 eV. When the duty cycle of the pulse was 1 - 10%, 7 - 8 eV He ion irradiation have contributed to the fuzz growth in addition to high (> 60 eV) energy ion irradiation, and the growth rate was enhanced.