部分PWO:Y3+晶体辐照后光产额升高,并且辐照硬度对退火温度较敏感.本文选取未掺杂及Sb、La3+、Y3+单掺和La3+/Sb、Y3+/Sb双掺的PWO样品进行对照实验,同时选取代表性晶体的顶部急冷料做了X射线荧光主量分析.结果发现:低剂量辐照后光产额升高现象只存在于含Y3+离子的PWO晶体中,并且这类晶体往往存在420nm吸收带;在改进Bridgeman法生长PWO晶体的后期,使熔体保持一定程度的负电性将有利于抑制该现象,即可有效地抑制同样是负电性的间隙氧进入晶体.结合测试数据,本文讨论了该现象的起因和机理,提出了掺杂剂的选择原则.
The light yield of some Y3+ doping PbWO4 crystals increases after low dose rate irradiation, and
the radiation hardness is sensitive to annealing temperature. In this study, the experiments among Sb, La3+, Y3+ doping and La3+/Sb,
Y3+/Sb co-doping PWO crystals were carried out, the composition of the melt in the top of the crystals was also measured by the XRF method. The
experimental results show that this exceptional behavior only exists in PWO crystals containing Y3+ ions. In addition those crystals have 420nm
absorption band in optical transmission spectra. In the processes of PWO crystal growth by the modified Bridgeman method, it is salutary to keep the melt
in a negative charge environment, thus preventing the formation of interstitial oxygen. Integrating with the data obtained, the mechanism of this phenomenon
was discussed, and the principles of choosing dopants to suppress it were also brought forward.
参考文献
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