高振动激发K_2与CO_2间弱碰撞和强碰撞的分支比  

Branching ratios of weak and strong collisions:highly vibrationally excited K_2( v″) with CO_2

作　　者：王淑英[1] 阿拜·艾力哈孜 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 [2]西安交通大学理学院,西安710049

出　　处：《原子与分子物理学报》2015年第5期805-810,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11364042)

摘　　要：受激发射泵浦激发K2到X1Σ+g(v″=40,53)振动态.K2(v″)与CO2碰撞,瞬时泛频激光诱导荧光(LIF)测得CO2(0000,J)的初生态布居,其半对数描绘给出了双指数分布.在池温为600 K时,对于v″=40和53,低转动温度T,分别为581±70 K与621±76 K,而高转动温度分别为1395±167 K与1556±187K.T1和T2分别对应于弱碰撞和强碰撞.转动分布对K2(v″)的能量是敏感的,但弱,强碰撞分支比基本相同.利用瞬时泛频LIF强度的相对变化,得到CO2J态的出现和倒空速率系数.确定了CO2平均角动量改变<ΔJ>和平均反冲速度改变<Δvrel>间的关系.对于相同角动量的改变,K2(v″)能量增加25%,反冲速度增加约47%.对于K2(v″=40,53)-CO2碰撞,得到了能量转移概率分布函数P(ΔE).By using a stimulated emission pumping technique, highly vibrationally excited K2X^1Σg^＋ （v＂ =40,53）states are obtained. The full states I resolved distribution of scattered GU2 （0000,J ） molecules Irom comslons with K2（v＂） is reported. The nascent CO2 （0000, J） populations are obtained from transient overtone laser in- duced fluorescence line intensity. The semilog plot of the rotational distribution showed the biexponential distri- bution. For K2 （v＂ = 40） ＋ CO2 at 600 K, the data set yield low and high - temperature distributions with T1 = 581±70 K and 7＇2 = 1395 ± 167 K, respectively. T1 corresponds to a weak collision and T2 is associated with a strong collisions. For K2（v＂ =53）, T1 =621±76 K and T2 = 1556 ± 187 K have been obtained. The spread of the rotational distribution is sensitive to K2 energy, but the branching ratios for both the weak and strong collisions are the same for the K2 energy. The relative changes of the transient overtone LIF intensities yield appearance and depletion rate constants. The correlation between the average change in angular momentum 〈 ΔJ 〉 of CO2 and the average change of recoil velocity 〈 Avro1 〉 are determined. By increasing the K2 （v＂） energy by 25%, the recoil velocities increase by - 47% for the same average changes in CO2 angular momentum. The full energy transfer probability distribution function P（AE） for K2 （v＂） - CO2 collisions is presented.

关 键 词：碰撞能量转移 弱碰撞和强碰撞 受激发射泵浦 速率系数 角动量改变 K2(v″)+CO2 

分 类 号：O561.5[理学—原子与分子物理]