| Summary: | 博士 === 國立清華大學 === 原子科學系 === 91 === Polycrystalline diamond film that is made by chemical vapour deposition (CVD) method used as thermoluminscent dosimeter for radiation detection has received considerable attention. This crystal has the advantages of tissue equivalence, chemical stability and non-toxicity; these make it an attractive material in dosimetry.
In this work, the predictions of theoretical thermoluminescent properties are determined by tigh-binding model and single-event track-structure Monte Carlo simulation. The former is based on quantum chemistry matrial science. The later is always used to calculate low energy x-ray transportation track and microdosimetric distribution.
Although the experiments are based on macroscopic methods, the microscopic studies are needed to solve the disagreement between theoretical macroscopic results and experimenta data. The predicted value of activation energy by tight binding model is 0.9 eV while the experimental result is 0.89?0.13 eV. The thermoluminscent properties of vacancy defect with hydrogen binding that are predicted to be light sensitive but obvious fading. These are also found in experimental results. However, the relative efficiency for low energy x-ray and radiation damage does not agree with the theoretical prediction.
A modified one-hit model is used to correct the differences. Based on the microscopic target model, some mechanistic insight into the physical aspect of radiation interaction with solid detectors can be obtained. This solid-state detector model shows that the response of radiation is similar to that of some biological system.
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