Crystal growth and scintillation properties of Nd:CaF2

Nd³⁺ doped CaF₂ single crystal scintillator has been investigated. We tried to grow 1%, 5%, 10%, 20%, 30% and 40% Nd³⁺ doped CaF₂ single crystals by the simple melt-solidifying method. Powder X-ray diffraction (XRD) patterns were measured to identify the phase of all the samples. The XRD patterns of all the samples were similar to CaF₂. Those samples are compared in terms of their X-ray-excited radioluminescence spectra, transmittance, α-ray-excited decay time and light yield. When the X-ray is used for excitation, luminescence is observed in the VUV region. Transmittance of the crystals is more than 70% at wavelengths longer than about 180 nm. In the decay kinetics, the fast components of the samples are distributed in less than 25 ns time range and the slow components of sample are distributed in more than 90 ns. These decay times became shorter with increasing Nd³⁺ concentration. They are related to the Nd³⁺ 5d-4f VUV emission. The light yields of samples are distributed in 5-2500 photon/5.5 MeV α-ray and decrease with increasing Nd³⁺ concentration.