摘要
采用慢正电子湮没光谱研究低能质子辐照下ZnO白漆的光学退化。研究结果表明,随质子辐照注量的增加,多普勒展宽谱的S参数逐渐减小,W参数逐渐增大。质子辐照下S-W参数拟合曲线的斜率发生改变。S参数的减小可以归结为锌空位含量的减少以及准正电子素的形成。准正电子素{单电离氧空位(捕获一个电子)+正电子}的形成,能够降低正电子湮没的速率,导致S参数减小。S参数的减小证实了质子辐照导致ZnO白漆中单电离氧空位数量的增加。S-W参数拟合曲线斜率的变化可以归结于质子辐照下双电离氧空位向单电离氧空位的转变。
The optical degradation in ZnO white paint under low energy proton exposure was investigated in terms of slow-positron annihilation spectroscopy. Experimental results show that with increasing proton fluence, the S-parameter of the Doppler broadening spectrum gradually decreases, and the W-parameter increases. The slope plot of the fitting S-W changes under the proton exposure. The decrease of S-parameter can be attributed to a decrease of zinc vacancy content and the formation of quasi-positroniums. The quasi-positronium is viewed as a bounded state of a singly ionized oxygen vacancy (trapping an electron) with a positron, the formation of which could reduce the positron annihilation rate and thus the S-parameter. The decrease of S-parameter demonstrates the amount increase of singly ionized oxygen vacancy of ZnO white paint caused by proton irradiation. The change of the S-W plot slope is related to the transformation of doubly ionized oxygen vacancies into singly ionized oxygen vacancies under proton irradiation.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2009年第10期1471-1475,共5页
High Power Laser and Particle Beams
基金
Supported by National Basic Research Foundation of China (61343010201)
关键词
慢正电子湮没
光学退化
ZnO白漆
质子
slow-positron annihilation
optical degradation
ZnO white paint
protons