Radiation Resistance of Composite Scintillators Based on Grains of Oxide Single Crystals.

A large number of experiments carried out at charged particle accelerators indicate that the radiation dose accumulated by the scintillation materials contained in detectors is significant. For example, in experiments at the Large Hadron Collider, the radiation dose in scintillation detectors can reach 10 Mrad and will increase in the future. In this connection, the search for new radiation-resistant scintillation materials is especially important. Irradiation can significantly alter the characteristics of the scintillator material. The aim of this work was to study the features of possible radiation damage and transformations in composite scintillators under the action of ionizing radiation. We focused on composite scintillators, which are transparent non-luminescent gel-compositions containing grains of scintillation oxide single crystals. A comparative analysis of the spectra of the relative light yield, transmission, and luminescence, as well as their dependence on the accumulated dose for various composite scintillators, has been carried out. Possible mechanisms of radiation changes occurring in scintillators under irradiation are proposed and the influence of these processes on the radiation resistant of composite scintillators is analyzed. In this work, as in previous works in this series, we irradiated composite scintillators on a linear electron accelerator. The electron energy was 10 MeV. We irradiated with a low (0.2 Mrad/h) and a high (1500 Mrad/h) dose rate. At low dose rate, cracking occurs at lower radiation dose values (about 100–200 Mrad) than under irradiation at a high dose rate (up to 500 Mrad). The luminescent characteristics of the scintillator changed insignificantly until the gel composition fixing single-crystal grains cracked. After destruction of the gel composition, an abrupt deterioration in the properties of the sample took place. [ABSTRACT FROM AUTHOR]