Radiation damage caused by swift heavy ions in CaF2 single crystals

• The RIOA and TSL were studied in CaF2 single crystals irradiated with SHIs.
• VUV absorption bands are connected with EEs localized near complex defects.
• There is some specificity of radiation damage under irradiation with Bi209 ions.

The radiation-induced optical absorption in a wide spectral region of 1.5–10 eV have been investigated in nominally pure CaF2 single crystals irradiated at 295 K with 0.23 GeV Xe132 or 2.38 GeV Bi209 ions (fluences of 1011−1014 ions/cm2) providing an extremely high density of electronic excitations. The stepwise annealing of the radiation-induced optical absorption have been analysed at the heating of irradiated crystals up to 1023 K and accompanying thermally stimulated luminescence has been detected at 300–750 K. The origin of several absorption bands (incl. vacuum ultraviolet region), the possible creation mechanisms of the corresponding radiation defects as well as the difference in radiation damage caused by Xe132 or Bi209 ions have been considered.