Na<sub>2</sub>高位振动态与CO<sub>2</sub>分子间碰撞能量转移的研究

摘要利用受激发射抽运将Na2分子激发到Na2 X 1 Σ +g (33，11)高位振动态，研究了高激发Na2与CO2的态-态能量转移过程。窄线宽激光扫描Na2的X 1 Σ +g (33，11)→ A1 Σ +u (21，10)跃迁，测量它的透射光强，从吸收系数得到Na2 X 1 Σ +g (33，11)原生态布居数密度。利用高分辨率瞬时吸收测量技术，得到CO2基振动态(0000)上转动态的布居数密度。通过速率方程分析，在一次碰撞的条件下，得到了与高振动激发Na2 碰撞产生CO2(0000)高转动态的速率系数。对于J=46~64，速率系数在4.5×10-12~6.5×10-13 cm3s-1之间，相对于J 态的Na2 ( ν″ =33)的猝灭速率系数在2.3×10-11~9.1×10-11 cm3s-1之间。实验数据表明，在Na2 高位振动态与CO2 的碰撞能量转移中，Na2 激发态倒空对CO2 转动能量的增加更有效。观察到了Na2高位振动态的多量子弛豫，得到了弛豫速率系数。

Abstract

Using stimulated emission pumping, the Na2 molecule is excited to Na2 X 1 Σ + g ( ν″ =33, J″ =11) high vibrational state, and the state- state energy transfer processes of the highly excited Na2 and CO2 are studied. Scanning Na2 X 1 Σ +g (33, 11)→ A1 Σ +u (21, 10) transition by narrow linewidth laser and monitoring its transmission light intensity, the original population density of Na2 [ X 1 Σ +g (33, 11)] is measured from absorption coefficient. Using highresolution transient absorption measurement technique, the distribution of CO2 rotational population in the ground (0000) state is determined. Through the analysis of rate equation, under the single- collision condition, the rate constants of CO2 (0000) high rotational state in the collisions with highly vibrationally excited Na2 are obtained. For J=46~64, the rate constants have been measured in 4.5×10-12~6.5×10-13 cm3s-1. Relatively to the J state, the quenching rate constants of Na2 ( ν″ =33) have been determined in 2.3×10-11~9.1×10-11 cm3s-1. The experimental data show that in the collisional energy transfer between highly vibrationally excited Na2 and CO2, the increase of CO2 rotational energy is much more sensitive to collisional depletion of excited state Na2. Multiquantum relaxation of highly vibrationally excited Na2 is observed and the relaxation rate constants have been obtained.

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王淑英, 张文军, 戴康, 沈异凡. Na₂高位振动态与CO₂分子间碰撞能量转移的研究[J]. 中国激光, 2015, 42(4): 0408001. Wang Shuying, Zhang Wenjun, Dai Kang, Shen Yifan. Study of Collisional Energy Transfer between Highly Vibrationally Excited Na₂ and CO₂[J]. Chinese Journal of Lasers, 2015, 42(4): 0408001.

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