Physical Sputtering, Blistering and Flaking Effect on Plasma-Facing Materials

Physical sputtering of Mo bombarded by Ar⁺, blistering and flaking of Mo implanted by He⁺ ions are described in the present paper. The sputtering yield of Mo was approximately constant in the energy range of 10–20 Kev while the sputtering yield vs. incident angle rose with increasing incident angle in the experiment. Blistering and flaking was observed in the ion fluence range of 7 × 10¹⁷ — 1 × 10¹⁹ ions/cm² but only surface protrusions become important when the ion incident angle was near 60°. It means that the sputtering became the dominant process comparing with blistering in this case. The “trackrace effect” of blistering has been found at room temperature and even inside the ion beam spot.