Color center creation in LiF crystals irradiated with 5- and 10-MeV Au ions

The peculiarities of defect creation in LiF crystals by irradiation with 5- and 10-MeV Au ions have been studied using optical spectroscopy. The crystals were irradiated at room temperature with fluences from 1 × 1012 to 2 × 1014 ions/cm2 at various beam current densities (1-200 nA/cm2). The short ion range in LiF allowed measurements for higher absorbed energy densities and high defect volume concentration. The efficiency of single F center and Fn and larger aggregate creation depends drastically both on ion fluence and flux (beam current). Color center creation is less effective for 5-MeV Au ions than for 10-MeV Au ions, which produce δ electrons with energies sufficient for creation of cation excitons (∼62 eV). The peculiarities of color center accumulation in LiF crystals under MeV Au ion irradiation are considered taking into account the nonlinear kinetics of interstitials (H centers).