Study of the scintillation properties and of the proton-induced radiation damage in the K₂CeCI₅ single crystal

In this paper, we report on the scintillation properties of the K ₂CeCl₅ single crystal before and after proton irradiation. The crystal of this scintillator was grown by using the Czochralski pulling technique and it was cut with dimension of 6 × 4 × 3 mm³. The scintillation properties, such as the absolute light yield, the proportionality of the response and the energy resolution, as functions of the γ-ray energy were calculated prior to the proton beam exposure. The light output deviates from a linear response by 10 % in the energy range between 31-keV and 1275-keV. Irradiation of the K₂CeCl₅ single crystal was carried out at the Korea Institute of Radiological and Medical Science. In order to measure the induced radiation damage in the K ₂CeCl₅ crystal, we subjected the sample to the 45-MeV proton beam of the MC-50 cyclotron and the scintillation properties were measured prior to and after the irradiation. The emission spectra before and after the irradiation showed the same emission band between wavelengths of 350 nm and 400 nm with a peak center at 375 nm. After exposure to the proton beam, the K₂CeCl₅ single crystal showed a lower light yield and a deteriorated energy resolution. In addition, we compared the decay time of the crystal before and after the proton irradiation.