Depths of the Regions Damaged by Protons, Deuterons and α-Particles in Lithium Fluoride Single Crystal

The depths of regions damaged by 0.6∼2.0 MeV protons, deuterons or α-particles penetrating the LiF single crystal were optically measured by utilizing the diffuse reflection of light from the metallic colloids formed by bombardment. The results were compared with the range-energy relations theoretically calculated on the Bethe formula. The depth data obtained agree well with the theoretical ranges with Z =10 or 12, depending on the bombarding ions, not with Z =6 which is usually taken for LiF. The rough approximation is given by the formulae with simple power of the energy value. As the sources of discrepancy between the depth of damaged region and the ion range, the following are possible: Channeling of the ions during penetration in the crystal and diffusion of the ion-induced defects.