H2诱导Cs（6DJ→Cs（7PJ′）碰撞转移截面  

Cross sections for Cs（6DJ）→Cs（7P（J′） collisional transfer processes induced by H2

作　　者：周冬冬[1] 王大贵[1] 王雪燕[1] 穆尼赛[1] 戴康[1] 沈异凡[1] 

机构地区：[1]新疆大学物理科学与技术学院,乌鲁木齐830046

出　　处：《激光杂志》2010年第1期28-29,共2页Laser Journal

基　　金：国家自然科学基金资助项目(10664003)

摘　　要：Cs蒸气置于十字交叉加热炉中,充入不同气压的H2,激光双光子激发Cs原子至6D3/2态,利用原子荧光光谱方法,研究了H2诱导6DJ→7PJ,的碰撞能量转移。测量不同氢气密度下直接6D3/2→6P3/2和敏化6D5/2→6P3/2,7P3/2→6S1/2和7P1/2→6S1/2的时间积分荧光强度,利用四粒子的速率方程分析,得到了6D3/2→7P3/2,6D3/2→7P1/2,6D5/2→7P3/2和6D5/2→7P1/2碰撞转移截面分别为(3.1±0.8)×10-16,(1.7±0.4)×10-16,(1.5±0.4)×10-16,(1.3±0.3)×10-16cm2。7PJ′态的猝灭截面分别为(2.5±0.6)×10-16cm2(对7P3/2)和(4.0±1.0)×10-16cm2(对7P1/2),它们主要是通过Cs(7PJ′)+H2→CsH+H反应产生的,而反应的相对活动性顺序为7P1/2>7P3/2。Cs vapor was created in a resistively heated,cross-shaped stainless-steel heat-pipe oven with quartz windows.H2 gas filled in the cell for use both as a buffer gas and as a reaction partner.Cs atoms were excited to 6D3/2 state by two-photon absorption.The 7P1/2 and 7P3/2 were populated by the radiative and collisional 6DJ→7PJ′ transition.The cross sections for 6DJ7PJ′ transfer induced by collision with H2 molecules have been determined using methods of atomic fluorescence.The resulting fluorescence included a direct component emitted in the decay of the optically excited state and sensitive component arising from collisionally populated states.The time-integrated fluorescence intensities for atomic transitions 6D5/2→6P3/2,6D3/2→6P3/2,7P3/2→6S1/2 and 7P1/2→6S1/2 were measured at the defferent H2 densities.The relative time-integrated population densities were obtained as a function of H2 densities.By the set of the rate equations,the cross-sections have been determined to be σ6D3/27P3/2=（3.1±0.8）×10^-16cm^2,σ6D3/27P1/2=（1.7±0.4）×10^-16cm^2,σ6D5/27P3/2=（1.5±0.4）×10^-16cm^2 and σ6D5/27P1/2=（1.3±0.3）×10^-16 cm2.The cross sections for quenching of 7PJ′ by H2 are（2.5±0.6）×10^-16 cm^2（for 7P3/2） and（4.0±1.0）×10^-16 cm2（for 7P1/2）.Evidence suggests that the substantial fraction of quenching cross section is reactive.The relative reactivity with H2 is an order 7P1/27P3/2.

关 键 词：激光光谱 碰撞能量转移 原子荧光:截面 Cs＊+H2 

分 类 号：O562.3[理学—原子与分子物理] O562.4[理学—物理]