where in the displacement energy is 40 eV [15,16]. SRIM 2008 was also used obtain corresponding displacements per atom (dpa) values, which were calculated to be 0.62 and 3.7 dpa, respectively. The calculations were achieved with ‘‘K-P quick calculation’’, and the dpa were obtained using the vacancy.txt file. The radiation damage depth(distribution) under 7 MeV Xe26+ ions was calculated to be 1400 nm, where the peak damage occurs at 900 nm.