An Annealing Treatment for Eliminating Residual Dose in CaF2:Mn

• Main Authors: Wang, Hsiang En, 王祥恩
• Other Authors: Weng, Pao Shan
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/64417751548457607515

博士 === 國立清華大學 === 原子科學研究所 === 84 === The conventional annealing and readout temperature for CaF2:Mn is 400℃. The TL which lies above the conventional readout and annealing temperature will accumulate after radiation exposures. Two effects caused by the residual TL are the residual phototransfer thermoluminescence (RPTTL) and thermoltransfer thermoluminescence (TTTL). The latter effect comes from the thermal dist6urbance. The thermal disturbance transfers the high temperature TL to the lower temperature glow peaks. A new annealing treatment for CaF2:Mn has been developed which can effecvtively erases the residual thermoluminescence (TL). The new method, which includes an optical as well as a thermal annealing process, is to expose the previously read CaF2:Mn chips to a 254 nm UV source with a power of 1.0 mW/cm2 for 40 min and then anneal the TLDs at 500℃ for 40 min. The experimental results show that RPTTL and the TTTL are effectively eliminated by the new annealing treatment.