痕量La杂质对CaF_(2)晶体γ辐照诱导色心光谱特性的影响

Effect of Trace La Impurities on the Spectral Properties of CaF_(2) Crystals withγ-Irradiation Induced Color Centers

氟化钙晶体的抗γ射线辐照性能是其在太空应用的关键性能之一。本文报道了痕量La杂质对氟化钙晶体γ辐照诱导色心的影响。主要采用吸收光谱、电子顺磁共振(EPR)等手段对辐照前后存在不同痕量La杂质的氟化钙晶体进行研究。结果表明,辐照后的氟化钙晶体产生多个色心吸收带,且吸收带的吸收系数随辐照剂量和La杂质浓度增加而增加。EPR证实这种吸收带的形成是由氟化钙晶体中F心引起的,而La^(3+)的存在影响氟化钙晶体F心的稳定性和光谱位置,本文提出了La^(3+)与氟化钙晶体中F心存在的可能机制。

The resistance of calcium fluoride crystals toγ-irradiation is one of the key properties for its application in space.In this paper,the effect of trace La impurities on theγ-irradiation induced color center of calcium fluoride crystals was reported.The calcium fluoride crystals with trace La impurities were studied by absorption spectroscopy and electron paramagnetic resonance(EPR).The results show that the irradiated calcium fluoride crystals produce multiple color center absorption bands,and the absorption band increases with the increase of irradiation dose and the concentration of La impurities.EPR confirms that the formation of this absorption band is caused by the F color center in the calcium fluoride crystal.The presence of La^(3+)affect the stability and spectral position of the F centers in calcium fluoride crystals.Possible mechanisms for the presence of La^(3+)and F centers in calcium fluoride crystals are proposed.