高低温条件下氟化锂材料的离子激发发光光谱分析

发布时间：2018-03-19 21:44

本文选题：离子激发发光　切入点：高低温　出处：《物理学报》2017年20期 　论文类型：期刊论文

【摘要】：在北京师范大学GIC4117串列加速器原有离子激发发光(ion beam induced luminescence,IBIL)分析靶室基础上,安装了可实现80—900 K温度范围内精确控温的冷热样品台,实现高低温条件下IBIL光谱的测量.添加金硅面垒探测器,在离子辐照材料样品过程中同步采集背散射离子的计数,实现束流的在线监测.在不同温度下,利用2 MeV H~+束轰击氟化锂样品,获得的IBIL光谱中可明显观察到温度对不同发光中心发光效果的影响:激子峰和杂质峰发光在低温条件下更为清晰;高温时各类型F色心的发光强度在较小的注量下即可达到饱和值或开始衰减.辐照初期受扰激子峰(296 nm)发光强度的上升过程表明不能排除受扰激子峰与点缺陷发光中心相关的可能性,激子峰强度的上升源自低注量时核弹性碰撞产生的应变键;温度对空位迁徙速率及非辐射复合的影响是造成发光强度随注量演变差异的重要原因.
[Abstract]:On the basis of the original ion-excited beam induced luminescence chamber of the GIC4117 tandem accelerator of Beijing normal University, a cold and hot sample table with accurate temperature control in the temperature range of 80-900K has been installed. The measurement of IBIL spectrum at high and low temperature is realized. The counting of backscattered ions is collected synchronously in the process of ion irradiating material samples with the addition of au Si surface barrier detector to realize the on-line monitoring of beam current. The effect of temperature on the luminescence of different luminescence centers can be observed in the IBIL spectra obtained by bombarding lithium fluoride with 2 MeV H- beam. The exciton peak and impurity peak are clearer at low temperature. At high temperature, the luminescence intensity of each type of F color center can reach saturation value or begin to attenuate at a relatively small flux. The rising process of the luminescence intensity of the perturbed exciton peak at the beginning of irradiation indicates that the disturbing exciton peak and the point defect can not be excluded. The possibilities associated with the center of light, The rise of exciton peak intensity originates from the strain bond produced by nuclear elastic collision at low flux, and the influence of temperature on vacancy migration rate and non-radiative recombination is an important reason for the variation of luminescence intensity with the flux.
【作者单位】：北京师范大学核科学与技术学院;北京市辐射中心;
【分类号】：O433.4

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