Abstract
熱發光材質應用於作為輻射劑量計已行之有年，而質子在研究及醫療上的重要性也漸漸地受到重視。研究主要觀察熱發光劑量計銩活化氟化鈣（CaF2:Tm, TLD-300）及鏑活化氟化鈣（CaF2:Dy, TLD-200）對質子的回應，可作為日後於質子治療時，劑量測定的參考。研究的質子源係由范氏加速器所產生，其能量範圍係在0.7到3.0 MeV 之間。實驗的方法則是改變所照射的質子能量、質子數目及照射的質子通量，以便瞭解各種照射情形對熱發光材質的影響。結果顯示CaF2:Tm 的第二峰與第五峰不但易於辨識，且輝光峰高度比值與照射質子能量呈良好的線性關係，所以很適合用來測定質子的能量。CaF2:Dy 由於對質子的靈敏度極高，因此適於用來測量微量的質子。Thermoluminescent material has long been used to determine theradiation dose. The proton research and therapy are becomingmore important, now. In our study the response of CaF2:Tm andCaF2:Dy to protons will provide the dose data for proton therapyin future.The source of proton beam was from by a Van de Graaffaccelerator with an energy range between 0.7 to 3.0 MeV. Wehave analyzed the influences of various proton energies, protonnumber and fluence on the response of CaF2:Tm and CaF2:Dy. Theresults show that CaF2:Tm with well defined peak 2 and peak 5 isan optimum dosimeter for the determination of proton energy bymeans of peak height ratio of peak 2 and peak 5. The moresensitive CaF2:Dy is an optimum dosimeter for measuring low-level proton radiationFoe the photon experiment, the new material MgB4O7:Dy,Na wasinvestigated with reference to annealing procedure. This newmaterial can approximately determine the absorbed dose of humanbody since its effective atomic number is close to that oftissue. Its glow curve is rather simple, with only one welldefined peak about 210o C. The proper annealing procedure forthis material will insure its applications. The method used wasto analyze the reproducibility while exposed to gamma. Afterproper annealingost residual TL of MgB4O7:Dy,Na can beeliminated. The results show that at 550o C for 2 h, theannealing procedure can retain the least TL residual, providehigh reproducibility and good linearity of a large dose range.