Influence of annealing on the optical and scintillation properties of CaWO single crystals
Influence of annealing on the optical and scintillation properties of CaWO single crystals
复制标题
退火对CaWO单晶光学和闪烁性能的影响
DOI：
10.1016/j.optmat.2012.05.014
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发表时间：
2012
影响因子：
3.9
通讯作者：
A. Zoller
中科院分区：
文献类型：
--
作者：
M. Sivers;C. Ciemniak;A. Erb;F. Feilitzsch;A. Gutlein;J. Lanfranchi;J. Lepelmeier;A. Munster;W. Potzel;S. Roth;R. Strauss;U. Thalhammer;S. Wawoczny;M. Willers;A. Zoller
我们研究了氧退火对用于直接暗物质搜索实验的CaWO4单晶的室温光学和闪烁性质的影响。所采用的退火法使闪烁光谱(∼430 nm)峰位的吸收系数降低了∼6倍，使散射系数的降低幅度更大。此外，退火对本征光产额没有显著影响。在∼400 nm处发生的额外吸收表明形成了O-空穴中心。单晶表面机械粗糙的室温光产额测量表明，退火后晶体的光产额提高了∼40%，59.5keV的能量分辨率提高了∼12%。我们将这一结果归因于吸收系数的降低，同时需要表面粗化来补偿退火后也观察到的散射系数的降低。
We investigate the influence of oxygen annealing on the room temperature optical and scintillation properties of CaWO4single crystals that are being produced for direct Dark Matter search experiments. The applied annealing procedure reduces the absorption coefficient at the peak position of the scintillation spectrum (∼430nm) by a factor of ∼6 and leads to an even larger reduction of the scattering coefficient. Furthermore, the annealing has no significant influence on the intrinsic light yield. An additional absorption occurring at ∼400nm suggests the formation of O-hole centers. Light-yield measurements at room temperature where one crystal surface was mechanically roughened showed an increase of the measured light yield by ∼40% and an improvement of the energy resolution at 59.5keV by ∼12% for the annealed crystal. We ascribe this result to the reduction of the absorption coefficient while the surface roughening is needed to compensate for the also observed reduction of the scattering coefficient after annealing.