掺稀土硫酸盐的剂量响应特性

Dose responses of alkaline-earth sulfate doped with rare earth ions

测量了掺稀土碱土硫酸盐的热释光和光释光剂量响应曲线,利用复合作用剂量响应模型,得出了剂量响应的非线性参数。实验发现剂量响应的线性与稀土离子的种类及其引起的缺陷结构相关。掺入Eu的磷光体材料的一次作用因子R接近于1,说明其响应是亚线性,以一次作用响应为主;掺入Tm和Dy的磷光体材料的一次作用因子R小于0.5,说明其响应是超线性,以二次作用响应为主。热释光峰温愈高,R因子越小,超线性愈严重,表明二次作用响应所占的份额增加。实验中光释光剂量响应的非线性参数和TL的参数基本相同。

Thermoluminescence (TL) and optical stimulated luminescence (OSL) dose response curves of alkaline-earth sulfate doped with rare earth ions were measured. The non-linear dose response parameters were obtained by using the composite action dose response model. It is concluded that the linearity of dose response is relative to the species of rare earth ions and the defect structure. The one-hit factors (R) are closes to 1 in sulfate phosphors doped with Eu ions, which means that the dose responses are sublinear. But the dose responses are supralinear since R less than or equal 0.5 when sulfate phosphors were doped with Tm or Dy ions. The value of R decreases with the increasing of TL peak temperatures, which means that contribution to dose response from the two-hit events is increased. The experiments also show that the dose response parameters of OSL are similar to those of TL.