Noriaki Kawaguchi

Crystal Growth and Scintillation Properties of Ce3+ and Mg2+ Co-Doped LiCaAlF6 Single Crystal

Ce and Mg Co-Doped LiCaAlF6 (LiCAF) Single Crystals Were Grown by Micro-Pulling-down (μ-PD) Method and the Optical and Scintillation Properties of Obtained Crystals Were Measured. The Grown Crystals Were Crack-Free and Had 30-50 mm in Length and 2 Mm in Diameter. Absorption Coefficients Were Proportional to the Ce Nominal Concentrations. the Radioluminescence Spectra under 5.5 Mev Alpha-Ray Irradiation Showed Emission Peak at 290 and 310 nm due to Ce3+ 5d-4f Transitions, and Were Agreement with those of Ce Single-Doped LiCaF. The Highest Light Yield under 5.5 Mev Alpha-Ray Irradiation of Ce 4% and Mg 2% Co-Doped LiCaF Was Found to Be 0.6 Times than that of Lithium Glass Scintillator GS-20. Comparing the Light Yield of Licaf Samples with the Fixed Ce Nominal Concentration and Different Mg Co-Doped Concentrations, the Light Yield Increased with an Increase of Mg Nominal Concentration. the Alpha-Ray Excited Decay Times Were Constantly 45-50 ns.

Growth and scintillation properties of Nd doped LiCaAlF 6 scintilltor

Nd³⁺ 0.5% doped single crystal LiCaAlF<inf>6</inf> scintillator was grown by the micro-pulling down (μ-PD) method. It was cut and polished to the physical dimension of 1 × 2 × 7 mm³. In transmittance spectrum, Nd³⁺ 5d-4f absorption observed at 175 nm and the transmittance became 80% at wavelength longer than 180 nm. Excited by 160 nm, Nd³⁺ 5d-4f emission appeared at 180 nm. X-ray induced radio-luminescence spectrum showed the similar feature with the photoluminescence one. When coupled with PMT and irradiated by ²⁴¹Am α-ray, the absolute light yield resulted 50 ph/5.5 MeV α.