Cs(6P)激发态的辐射及与N2碰撞的能量转移

应用激光吸收和荧光方法,测量了Cs(6P)态与N2碰撞的精细结构转移和碰撞猝灭截面。Cs原子被激光激发到6P3/2态,将与泵浦激光束反向平行的检测激光束调到6PJ→8S1/2的跃迁,测量了6PJ激发态的密度及空间分布,由此计算了6PJ→6S的有效辐射率。在T=337 K(蒸气压公式给出Cs密度N0=1.25×1012cm-3)和N2密度2×1016相似文献   

Rb(5 P_J)+(He、N_2)碰撞能量转移

在气体样品池条件下,研究了Rb(5PJ) (He、N2)碰撞能量转移过程.调频半导体激光器稍微调离共振线,激发Rb原子至Rb(5P3/2)态,在不同的He或N2气压下,测量了直接5P3/2→5S1/2荧光和转移5P1/2→5S1/2荧光.对于5PJ与He的碰撞.电子态能量仅能转移为He原子的平动能.在与N2的碰撞中,向分子振转态的转移是重要的.利用速率方程分析,可以得到碰撞转移速率系数,对于He,5P3/2→5S1/2转移速率系数为2.23×10-12cm3s-1.对于N2,测量5PJ He和5PJ N2二种情况下荧光的相对强度比,利用最小二乘法确定5P3/2→5S1/2转移速率系数为4.38×10-11cm3s-1,5PJ态猝灭速率系数为5.45×10-11cm3s-1.与其他实验结果进行了比较.     

A diffusion model for solute atoms diffusing and aggregating in nuclear structural materials

In nuclear structural materials, the nuclear irradiations induce the precipitations of soluble elements or produce the insoluble elements such as He atoms that may form clusters, heavily shortening the service life-times of the materials. In the present work, a diffusion model is developed to predict where and how fast the solute atoms(either soluble or insoluble)aggregate, and this model is applied to the study of the formation and growth of He bubbles in metal tritides(PdT_(0.6), ErT_2,NbT_(0.0225), VT_(0.5), TaT_(0.097), TiT_(1.5), ZrT_(1.6)) within one thousand days. The results are in good agreement with the available experimental observations and suggest that searching for metals with a barrier of more than 1.1 eV for a single He atom diffusion and making more defects in metal tritides can significantly reduce the growth of He bubbles and extend the service time of the metals.     

Rb—Ne光学碰撞精细结构转移截面

用非共振激光激发光学薄的Rb蒸汽和低密度Ne的混合系统，通过测量Rb5PJ的荧光强度，得到了RbNe态预离解率之比和Rb5PJ精细结构转移截面，分析了转移截面随压强变化的原因．     

Rb(5PJ)与He,N2的碰撞精细结构混合和猝灭

在气体样品池条件下,研究了Rb(5PJ) (He,N2)碰撞能量转移过程.用调频半导体激光器激发Rb原子至Rb(5P3/2)态,在不同的He或N2气压下,测量了直接5P3/2→5S1/2荧光和转移5P1/2→5S1/2荧光.对于Rb(5PJ)与He的碰撞,只发生精细结构转移(略去碰撞猝灭效应),电子态能量仅能转移为He原子的平动能.在与N2的碰撞中,向分子振转态的转移是重要的.本实验中,Rb的密度为4.5×1011 cm-3,由辐射陷获理论得到5P1/2→5S1/2的有效辐射率为2.47×107 s-1.利用速率方程分析,可以得到碰撞转移速率系数,对于He,5P3/2→5S1/2转移速率系数kHe21=2.61×10 12 cm3·s.对于N2,测量5PJ He和5PJ N2两种情况下直接荧光与敏化荧光的相对强度比,利用最小二乘法确定5Pa/2→5S1/2转移速率系数kN212=2.36×10-11 cm3·s,5PJ态猝灭速率系数kN2=1.44×10-11 cm3·s-1.由实验结果证实了Cs-N2主要是直线式碰撞传能机制,与其他实验结果进行了比较.