MgSO_4:Dy,P和MgSO_4:Dy,P,Cu的热释光剂量学特性  

Thermoluminescence dosimetric characteristics in MgSO_4:Dy,P and MgSO_4:Dy,P,Cu phosphors

作　　者：罗达玲[1] 唐强[1] 张纯祥[1] 

机构地区：[1]中山大学物理系,广州510275

出　　处：《核技术》2001年第12期1009-1019,共11页Nuclear Techniques

基　　金：国家自然科学基金项目 (19775 0 71);广东省自然科学基金项目 (990 2 15 )

摘　　要：MgSO4 :Dy中掺入适量的P ,热释光发光曲线中两个高温峰显著增强 ,主剂量峰的峰温接近2 83.6℃ ,另一个发光峰的峰温在 35 2 .7℃ ,其热释光效率超过LiF:Mg ,Ti的两倍。MgSO4 :Dy ,P的单个发光峰峰面积对60 Coγ辐射剂量 (0 .1Gy— 2 0kGy)的实验响应曲线用复合作用响应函数拟合 ,得到的非线性特征参数表明 ,两个发光峰的γ辐射剂量响应均为超线性。在MgSO4 :Dy ,P中再掺入微量Cu ,首先抑制峰温在 35 2 .7℃的发光峰 ,随着Cu浓度的增加 ,2 83.6℃的主剂量峰会随之降低 ,此峰的γ辐射剂量响应的超线性随之减小。MgSO4 :Dy ,P ,Cu (0 .1mol% ,0 .5mol% ,0 .0 1mol% )磷光体对γ辐射的剂量响应 (0 .1Gy— 2 0kGy)为亚线性。最引人注目的是MgSO4 :Dy ,P ,Cu(0 .1mol% ,0 .5mol% ,0 .0 0 4mol% )磷光体 ,它具有与MgSO4 :Dy ,P(0 .1mol% ,0 .5mol% )相近的热释光灵敏度 ,并具有最宽的剂量响应线性范围。这种新热释光材料可用于高剂量辐射测量。本文进一步阐明和验证了《复合作用模型》 ,并揭示了热释光材料中杂质和缺陷结构与剂量学特性的相关性。The two peaks at higher temperature in thermoluminescence (TL) glow curve of MgSO 4:Dy are enhanced when a certain amount of P was co-doped into MgSO 4:Dy. One main dosimetric peak at about 283.6 ℃ and a satellite peak at about 352.7 ℃ are involved in the TL glow curve of the MgSO 4:Dy,P. The TL sensitivity of MgSO 4:Dy,P phosphor is two times higher than that of LiF:Mg,Ti. The dose responses to gamma rays in the dose range from 0.1Gy to 20kGy were obtained and fitted by the composite action dose response function to get the nonlinear characteristic parameters which indicate that the TL dose responses for the two peaks of MgSO 4:Dy,P are supralinear. While a trace amount of Cu was co-doped into MgSO 4:Dy,P the TL glow peak at 352.7 ℃ was suppressed and the TL sensitivity and the nonlinearity of dose response for the main dosimetric peak at 283.6℃critically depends on the concentration of dopant Cu. The dose response of MgSO 4:Dy,P,Cu (0.1 mol%, 0.5 mol%, 0.01 mol%) phosphor is linear-sublinear. The MgSO 4:Dy,P,Cu (0.1 mol%, 0.5 mol%, 0.004mol%) phosphor has a wider linear range in the dose response than MgSO 4:Dy,P(0.1 mol%, 0.5 mol%) and its TL sensitivity is close to MgSO 4:Dy,P (0.1 mol%, 0.5 mol%). It may be a candidate to measure radiation dose under higher dose circumstances. Furthermore, the composite action model was described further. The experimental results of the MgSO 4:Dy,P and MgSO 4:Dy,P,Cu obtained in this work show that the dosimetric properties of TL materials are linked with the defect structure in these materials, which is useful for understanding the TL mechanism of sulphates with cooperating the TL 3D emission spectra of these phosphors.

关 键 词：热释光 剂量学特性 MgSO4:Dy P MgSO4:Dy P CU Γ剂量计 复合作用机制 剂量学材料 辐射剂量剂 铜 磷 镝 硫酸镁 掺杂 稀土 

分 类 号：TL818.4[核科学技术—核技术及应用] O483[理学—固体物理]