Optical characterization of neutron detection crystal Li 6 Gd(BO 3 ) 3 :Ce

Colorless and transparent Li 6 Gd(BO 3 ) 3 :Ce crystals are grown with the Czoralski method. Their optical characteristics and luminescence processes are also investigated. The ultraviolet-vaccum ultraviolet (UV-VUV) transmittance spectra are measured and the result shows that absorption peaks due to Ce 3+ ions and Gd 3+ ions, and the absorption band related to charge transfer band of Ce 4+ ions are present. According to the UV-VUV excitation and emission spectra, it is found that there appear luminescences of 5d→4f radiative transitions of Ce 3+ ions and of 4f→4f radiative transitions of Gd 3+ ions, and also Gd 3+ →Ce 3+ energy transfer. The X-ray and γ-ray stimulated luminescence spectra show that the scintillation light of the crystal is mainly from Ce 3+ ions.