Abstract：The electronic to rovibrational energy transfer between the high-lying 61Σ+ state of NaK and H2 was investigated. The 61Σ+ state was excited using the optical-optical double resonance technique. Radiative processes were monitored by fluorescence from the 61Σ+ state to the ground 11Σ+ state. The CARS (coherent anti-Stokes Raman scattering) spectral technique was used to probe the internal state distribution of collisionally-populated H2 molecules. The scanned CARS spectra reveal that during E-V, R energy transfer processes H2 molecules are produced at v=1, 2 and 3 levels. The semilog plot of the time-resolved H2 (3, 1) CARS intensity was obtained at a pressure of 4×104 Pa of H2. The slop yields an effective quenching rate of 8.09×105 s-1. Analogically, for (3, 2), (3, 3) and (3, 5) levels, the quenching rates are 6.11×105, 4.32×105 and 2.45×105 s-1, respectively. For (3, 1), (3, 2), (3, 3) and (3, 5) levels, the population ratios were obtained from scanned CARS spectral peaks. For (1, 1), (2, 1), (2, 2) and (2,3) levels, from scanned CARS spectral peaks two possible population ratios were yielded. Through shape simulations of time resolved CARS profiles under a kinetic model the actual population ratios were determined. The n2/n1, n3/n1, n4/n1, n5/n1, n6/n1, n7/n1and n8/n1 are 0.51, 0.97, 0.45, 0.18, 0.10, 0.26 and 0.31, where n1, n2, n3, n4, n5, n6, n7andn8 represent the number densities of H2 at (3, 1), (2, 1), (1, 1), (3, 3), (2, 3), (2, 2), (3, 2) and (3,5 ) levels, respectively. The H2 molecules produced by energy transfer process were populated by 26% at the v=1 level, 21% at v=2 and 53% at v=3. The major vibrational energy [(9.0±2.7)×103 cm-1] release and the minor rotational energy [(3.9±1.1)×102 cm-1] release are shown. Based on the Stern-Volmer equation, the radiative lifetime is (5.0±1.3) ns for the 61Σ+ state, the total rate coefficient for deactivation of 61Σ+ state by means of collisions with H2 is (2.1±0.4)×10-10 cm3·s-1. From actual population ratios the rate coefficients (in units of 10-11 cm3·s-1) for 61Σ+-(1, 1), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3) and (3, 5) are 5.4±1.6, 2.8±0.8, 0.6±0.2, 1.0±0.3, 5.6±1.7, 1.4±0.4, 2.5±0.8 and 1.7±0.5, respectively.
Key words：Laser spectroscopy;E-V. R energy transfer;CARS spectrum;Rate coefficient;NaK (61Σ+)-H2
王淑英1,2，戴 康2，刘 静1,2，沈异凡2* . NaK(61Σ+)与H2碰撞传能中的H2的振转态分布 [J]. 光谱学与光谱分析, 2012, 32(12): 3183-3187.
WANG Shu-ying1, 2, DAI Kang2, LIU Jing1, 2, SHEN Yi-fan2* . Rovibrational State Distributions of H2 in Collisional Energy Transfer between NaK (61Σ+) and H2. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2012, 32(12): 3183-3187.
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