K_2(9~1∑^+_g)高位电子态与H_2碰撞中H_2的能量分布

Energy Distributions of H_2 in Collisions between High Lying K_2(9~1∑^+_g) and H_2

光学-光学双共振激发K2到91∑+g高位态,研究了K2(91∑+g)与H2的电子-振转碰撞能量转移。利用相干反斯托克斯(CARS)光谱技术探测H2的振转态分布,扫描CARS谱表明H2在(1,1)、(2,1)、(2,2)、(3,1)、(3,2)、(3,3)和(3,5)能级上有布居。由时间分辨CARS轮廓得到H2各振转能级上粒子数之比,得到H2的平均振动能和平均转动能分别为9063cm-1和388cm-1。从91∑+g→11∑+u、11∑+u→11∑+g、33∏g→13∑+u跃迁的时间分辨激光感应荧光(LIF)强度得到它们的自发辐射率和碰撞转移率。在H2压强为3×103Pa时,K2(91∑+g)与H2的碰撞转移能为16930cm-1。H2的平均振转能占平均转移能的56%。

The electronic to rovibrational energy transfer between the high-lying 9^1∑g^＋ state of K2 and H2 has been investigated. The 9^1∑g^＋ state is excited using the optical-optical double resonance. The CARS （Coherent Anti-Stokes Raman Scattering） spectral technique has been used to probe the internal state distribution of collisionally-populated Hz mole- cules. The scanned CARS spectra reveal that H2 molecules are produced at （1,1）, （2,1）, （2,2）, （3,1）, （3,2）, （3,3） and （ 3,5 ） levels. The actual population ratios are determined through time resolved CARS profiles. The major vibrational energy （9063 cm-l） release and the minor rotational energy （388 cm-1） release are shown. The decay signals of the time-resolved fluorescene [rom 9^1∑g^＋→1^1∑u^＋、l^1∑u^＋→1^1∑g^＋ and 3^3Ⅱg→1^3∑u^＋ transition are monitored. Based on Stern-Volmer equation, radiative rates and collision transfer rates of three states 9^1∑g^＋ ,l^1∑u^＋ and 3^3Ⅱg have been determined. In PH2 =3×10^3Pa,the fer energy （16930cm-1） is obtained. The efficiency of the electronic-to-rovibrational transfer is 56% for the K2 9^1∑g^＋-H2 system. trans- energy