The Response of Thermoluminescent Dosimeter to Proton and Photon

• Main Authors: Tsai, Lei Jane, 蔡麗貞
• Other Authors: Pao-shan Weng
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/98269414925686617470

碩士 === 國立清華大學 === 輻射生物研究所 === 85 === Thermoluminescent material has long been used to determine the radiation dose. The proton research and therapy are becoming more important, now. In our study the response of CaF2:Tm and CaF2:Dy to protons will provide the dose data for proton therapy in future. The source of proton beam was from by a Van de Graaff accelerator with an energy range between 0.7 to 3.0 MeV. We have analyzed the influences of various proton energies, proton number and fluence on the response of CaF2:Tm and CaF2:Dy. The results show that CaF2:Tm with well defined peak 2 and peak 5 is an optimum dosimeter for the determination of proton energy by means of peak height ratio of peak 2 and peak 5. The more sensitive CaF2:Dy is an optimum dosimeter for measuring low- level proton radiation Foe the photon experiment, the new material MgB4O7:Dy,Na was investigated with reference to annealing procedure. This new material can approximately determine the absorbed dose of human body since its effective atomic number is close to that of tissue. Its glow curve is rather simple, with only one well defined peak about 210o C. The proper annealing procedure for this material will insure its applications. The method used was to analyze the reproducibility while exposed to gamma. After proper annealingost residual TL of MgB4O7:Dy,Na can be eliminated. The results show that at 550o C for 2 h, the annealing procedure can retain the least TL residual, provide high reproducibility and good linearity of a large dose range.