在医学放射治疗上可以利用Al2 O3：C晶体产生的辐射发光（ Radio－luminescence，RL）测量放射治疗的剂量率。本文采用双电子陷阱双复合中心动力学模型对Al2 O3：C晶体的辐射发光剂量特性做了数值模拟，给出了β射线辐照Al2 O3：C晶体过程中各能级上载流子和RL产生的动态过程，并首次数值模拟了F＋中心浓度和高剂量辐照对RL的影响。模拟结果表明：β射线连续辐照Al2 O3：C时其产生的RL强度由初始值达到平衡值，且初始值和平衡值都与剂量率成正比，随着Al2 O3：C晶体中F＋中心浓度的增加，RL强度增强，初始值和平衡值都增加，最后给出了高剂量辐照Al2 O3：C晶体对RL的影响。文章中数值模拟的结果和先前实验结果相一致，同时模拟结果对Al2 O3：C晶体在制备过程中如何提高RL强度从理论上指明了方向。%Radio-luminescence from carbon-doped aluminum oxide ( Al2 O3:C) crystal can be used for dose rate measurements in radiotherapy.In this paper,we numerically simulate dose characteristics of RL in Al2 O3:C crystals using a kinetic model involving two electron traps and two kinds of recombination centers, dynamic processes for the charge carriers of different levels are given during Al2 O3:C is irradiated, the effect of the F+center concentration and high dose on the RL are numerically simulated for the first time.Simulation results show that the RL intensity rises from initial value to balance value when Al2 O3:C crystal is radiated, both the initial value and balance value varies linearly with the dose rate.The RL intensity increases with the increase of F +center concentration in Al2 O3:C, the initial value and balance value increases correspondingly, finally the influence of high dose on the RL is given.The numerical simulation results in this paper are in good agreement with the previous experimental results.Meanwhile, the simulation results point out theoretically that the direc-tion on how to enhance the RL intensity in the preparation of Al2 O3:C crystal.
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