H_2(V=3)+H_2(He)碰撞中的转动能量转移  

Rotational energy transfer of H_2(V=3) in collisions with H_2 and He

作　　者：张彬[1] 朱冬辉[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：《原子与分子物理学报》2012年第4期645-649,共5页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10964011)

摘　　要：激发态Na_2与H_2碰撞,使H_2(V=3,J=3)得到布居,在H_2和He总气压为800 Pa及温度为700 K的条件下,利用相干反斯托克斯拉曼散射(CARS)光谱技术研究了H_2(3,3)与H_2(He)间转动能量转移过程.改变CARS激光束与激发Na_2的激光之间的延迟时间,测量He不同摩尔配比时H_2(3,J)态CARS谱强度的时间演化,得到H_2(3,3)的总弛豫速率系数分别为k_(3,3)^(H_2)=(21士5)×10^(-3)cm^3·s^(-1)和k_(3,3)^(H_e)=(5.6士1.6)×10^(-13)cm^3·s^(-1).测量H_2(3,J)各转动态的相对CARS谱强度,由速率方程分析,得到H_2(3,3)+H_2→H_2(3,J)+H_2中,对于J=2,4,转移速率系数分别为(11±4)×10^(-13)cm^3·s^(-1)和(8.2±3.1)×10^(-13)cm^3·s_^(-1).在H_2(3,3)+He→H_2(3,J)+He中,对于J=2,4,转移速率系数分别为(3.1±1.2)×10^(-13)cm^3·s^(-1)和(2.1士0.7)×10^(13)cm^3·s^(-1).对于H_2(3,3),单量子弛豫|△J|=1约占该态总弛豫率的90%.The electronic to rovibrational energy transfer between electronically excited Na2 and H2 was employed to produce H2（v=3,J=3）. Rotational relaxation rates for H2（3,3） colliding with H2 and He at 700K have been measured using a CARS（Coherent Anti-Stokes Raman Scattering） spectral technique. Collision-induced population transfer events were observed at total pressure of 800Pa. The population evolution in the prepared state and the collision-induced rotational states was monitored by the time delay between the excitation pulse and the probe pulses. The plots of the time evolution CARS intensities in the different mol fractions of He yield relaxation rate coefficients （in 10-13cm3s-1） for collisional transfer out of H2（3,3） are =21±5 and =5.6±1.6cm3s-1，respectively. Through the time evolution and relative intensities of CARS of collisionally populated rotational states under a simple kinetic model，the rotational transfer rate coefficients were obtained. The rate coefficient （in units 10-13cm3s-1） for H2（3,3）＋H2→H2（3,J）＋H2 for J being 2 and 4 are 11±4 and 8.2±3.1，respectively. The rate coefficients （in units 10-13cm3s-1） for H2（3,3）＋He→H2（3,J）＋He for J being 2 and 4 are 3.1±1.2 and 2.1±0.7，respectively. These show that single quantum relaxation J=1 accounts for 90% of the total relaxation out of state J=3.

关 键 词：碰撞能量转移 CARS光谱技术 布居数演化 速率系数 H2-He 

分 类 号：O561.5[理学—原子与分子物理]