Radioluminescence of rare-earth doped potassium yttrium fluorides crystals

The radioluminescence (RL) properties of K 2YF 5 crystals doped with Ce 3+, Tb 3+ and Dy 3+ under ionizing irradiation excitation have been studied for the first time. The main objective of this work has been to assess the feasibility of using these crystals as detectors for fiberoptic radioluminescent dosimetry. In particular, it has been found that the RL intensity from both K 2YF 5:Tb (10%) and K 2TbF 5 is comparable to that from a commercial Al 2O 3:C crystal. Longer wavelength emission from these fluorides makes simple optical filtering technique possible to use in order to avoid the stem effect. Afterglow decay times for these fluorides have been found to be similar to that for Al 2O 3:C and, in particular, K 2TbF 5 does not show longer afterglow decay time compared to Al 2O 3:C.