THERMOLUMINESCENCE DOSE MEASURING ELEMENT AND RADIATION DETECTOR

摘要

PROBLEM TO BE SOLVED: To shift a thermoluminescence glow peak temperature to a higher temperature region and in addition inhibit transition of excited electrons to a ground state due to crystal defects thereby keeping an excited state immediately after radiation exposure for a long time.;SOLUTION: Into CaF₂ as a base material, 0.1 mol% of TbF₃, 0.5 mol% of GdF₃ and 0.1 mol% of SmF₃ are mixed and melted to grow a single crystal of CaF₂. By irradiating the single crystal with X rays and evaluating glow peak intensity, a small peak can be confirmed around 80°C (low temperature region), and a large peak can be confirmed around 400°C (high temperature region). By thus making the peak in the low temperature region relatively smaller than the peak in the high temperature region, an F center of added Tb electrons becomes stable, and energy transition is hard to occur from the F center to the ground state with the passage of time. Therefore, the excited state immediately after exposure of radiation such as X rays can be kept for a long time.;COPYRIGHT: (C)2011,JPO&INPIT