Surface Damage of Stainless Steels by Helium Ion Bombardment

He reemission implanted in metals

“…5 and 6. This was caused by multi-layered blistering which was clearly observed in SEM images of irradiated Ni surfaces by 20 keV [8] and 500 keV [7] He ions at 500°C. The periodic behavior continues, even after once the implantation was interrupted as shown in Fig.…”

“…Above the critical fluence, the large bubbles near surface (blisters) rupture and a new surface behind is exposed to produce second blistered layers [1,2,7,8]. This causes the periodic reemission behavior with a nearly constant period of fluence.…”

“…10, variation of reemission behavior with the normalized temperature (T m ) by the melting point of each metal can be characterized into four different temperature ranges. Here we have tried to correlate He reemission, He migration and microstructure developed by He implantation [1,2,[6][7][8][9][10][11] for four temperature ranges as follows. Although Sinha et al [7] gave clear temperature dependence of He blistering in Ni, their incident energy of He ions of 500 keV was too high to observe fuzz structure or more detailed surface structure appeared in Fig.…”