NGHIÊN CỨU SỰ PHỤ THUỘC NĂNG LƯỢNG PHOTON BẰNG THỰC NGHIỆM VÀ TÍNH TOÁN ĐỐI VỚI VẬT LIỆU CaSO4:Dy VÀ Al2O3:C

Abstract

In this work, the energy dependence of thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) for photon by the computational and experimental results were studied. Mass energy-absorption coefficients [in µ_en/ρ (cm²/g)] for calcium, sulfur, oxygen, aluminum, carbon, and dysprosium using a Mathematica software were calculated. For materials composed of various elements, it is assumed that the contribution of each element to the total interaction of the photon is additive “mixture rule.” The results obtained from the experiments and the computation were normalized to ¹³⁷Cs energy response. Within method uncertainty, the calculated energy dependency shows an agreement with experimental results. Both CaSO₄:Dy powder (Made in Dalat Nuclear Research Institute) and Al₂O₃:C dosimeters (InLight Basic, Landauer Inc., USA) showed very good uniformity, sensitivity, batch reproducibility, linearity, and low fading for a wide range of doses. Choosing the correct energy for TLDs’ calibration is an important factor that can affect the accuracy of the absorbed dose. The results showed that TLDs and OSLDs have a non-uniform response at different energies and both types of dosimeters are quite sensitive in the low photon energy region.