I.I. Vasilyev

This paper presents a study of gamma irradiation effects on the optical and scintillation properties of pure and yttrium-doped BaF ₂ crystals with yttrium concentrations of 1, 3, and 5 mol%. The optical transmittance, light output, and energy resolution of twenty-four 1×1×1 cm ³ samples were measured before and after ⁶⁰ Co gamma irradiation, with absorbed doses up to 3.56 Mrad. In pure BaF ₂ samples, no noticeable degradation in scintillation properties was observed with increasing absorbed dose. In yttrium-doped samples, a deterioration of scintillation properties is observed, with the fast component of crystal luminescence deteriorating more than the slow one. The correlation between the loss of light output and the radiation-induced decrease of optical transmittance, together with the absence of structural changes in Raman spectra, indicates that the degradation of scintillation properties is primarily due to increased self-absorption, rather than to disruption of the scintillation mechanism.

Based on an unconventional application of commercially available power GaN transistors, a voltage-sensitive amplifier circuit was proposed for a scintillation sandwich-type lead-plastic calorimeter cell using SiPMs, intended for detectors operating under high-radiation conditions. The radiation hardness of the selected GaN transistors under gamma irradiation was investigated. Defect formation in the transistor structures was studied using C-V characteristics. The results demonstrate that GaN transistors can serve as a promising element base for scintillation detectors operating in high-luminosity accelerator environments.

This paper presents the results of measuring the parameters of scintillation cubes, which are elements of the active target of the upgraded near detector of the T2K experiment, with the scintillation of a polystyrene-based organic scintillator being excited by an ultraviolet LED. Most attention is paid to the study of light leaks through the side faces of the cubes. The measurement results show that an average value of the coefficient characterizing light leaks through one face of the cube is 0.026. The effect of heating scintillation cubes on the light collection from them and light leaks are studied. After keeping the cubes at a temperature of 60°C for 72 h, the light collection from the cubes and the light leaks remained at the same level.