The 6th International Conference on Matter and Radiation at Extremes (ICMRE2023)

28 / 2023-04-02 16:47:57

Numerical simulation of photoluminescence characteristics of NaCl (Cu) crystal

Energy Level System,Numerical Algorithm,NaCl(Cu),Optically Stimulated Luminescent

High Pressure Physics and Materials Science > Functional materials and physics-poster

  In 2001, Bailey proposed a differential equation system for charge transfer rates in the quartz original model to describe the dynamic process of the energy level system. This article modified the model for NaCl(Cu) and used a combination of the charge transfer rate differential equation system and R language numerical algorithm to simulate the optically stimulated luminescence (OSL) characteristics of NaCl(Cu) crystals. The results showed that the OSL attenuation of NaCl(Cu) crystals at different temperatures varied after irradiation with doses of 0.5Gy, 1Gy, 5Gy, 10Gy, and 20Gy, and samples with the same irradiation dose exhibited higher sensitivity in the range of 110-140℃. During the 60-day storage of NaCl(Cu) crystals in a dark environment at room temperature, the OSL signal decayed very little or even showed "reverse decay", which may be related to the regeneration of "F centers" during the optical stimulation process. The overall change in OSL signal amplitude remained within 1%, much smaller than the experimental data on thermoluminescence attenuation in the literature. The OSL dose response of NaCl(Cu) crystals was linearly fitted with a correlation coefficient of 0.97 in the range of 0~100Gy, maintaining a good linear relationship and exhibiting a saturation trend only at 90Gy. However, the dose response results were obviously higher than the linear fitting results in the range of 0~5Gy. To address the problem of insufficient accuracy in linear fitting in the range of 0~5Gy, an optimized single-aliquot regenerative dose (SAR) readout scheme was used to read the dose, and a growth curve compensation SAR readout scheme was calculated to compensate for the error caused by changes in the sensitivity of NaCl(Cu) single crystals. Finally, the dose reading error remained within 7%, achieving more reproducible OSL signals. The simulation results revealed that NaCl(Cu) crystals have the characteristics of an excellent dose component, deepening our understanding of the physical mechanism of signal generation during optical excitation and providing basic results for subsequent experimental plans. Furthermore, the simulation results showed good consistency with the experimental data reported in the literature, indicating that this combination method can accurately predict the OSL characteristics of NaCl(Cu) crystals. Overall, this study provides valuable insights into the properties and behaviors of NaCl(Cu) crystals as dose components and contributes to the development of more accurate and effective methods for measuring radiation doses.