Crystal Growth and Scintillation Properties of Carbazole for Neutron Detection

Carbazole crystals were grown using self-seeding vertical Bridgman technique, and the scintillation properties for neutron detection were investigated. Results of powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses indicated the single phase of the grown carbazole crystal with orthorhombic structure. Photo- and radio-luminescence measurements were carried out, and maxima of both emission peaks were at 420 nm. The light yield under 5.5-MeV alpha-ray irradiation was estimated to be 1.87 times higher than that of lithium glass GS-20. The scintillation decay time under neutron irradiation was estimated to be 11.4 +/- 0.3 ns. It follows from the temperature dependence measurements that the light output under 662-keV gamma-ray excitation decreases with increasing temperature.