C2H22^1分子转动角动量定向分布（Orientation）及其碰撞弛豫和转移

THE ANGULAR MOMENTUM ORIENTATION OF C 2H 2 2 1 AND ITS COLLISIONAL DECAY AND TRANSFER 

利用圆偏振激光受激Ｒａｍａｎ抽运，以Ｃ２Ｈ２分子为样品选择性地制备了它的电子基态单一转动态Ｘ～１Σ＋ｇ，ν″２＝１，Ｊ″的角动量定向布居（ｏｒｉｅｎｔａｔｉｏｎ）．并从圆偏振紫外激光诱导的Ａ～１Ａｕ（ν′３＝１）←Ｘ～１Σ＋ｇ（ν″２＝１）的荧光（谱），直接测定了Ｃ２Ｈ２（Ｘ～１Σ＋ｇ，ν″２＝１，Ｊ″＝４，７，８，…，１３）的角动量定向布居值．从时间分辨的荧光信号谱测定了角动量定向布居的碰撞弛豫速率常数，同时还研究了由各初始激励的转动态向其他邻近转动态碰撞诱导的角动量定向布居转移．

Abstract The rotational angular momentum orientation of acetylene in vibrationally excited discrete rotational states X～ 1Σ + g, ν″ 2=1,J″ has been selectively prepared by circularly polarized laser stimulated Raman pumping. From the induced fluorescence by a circularly polarized UV laser, A～ 1A u( ν′ 3=1)← X～ 1Σ + g( ν″ 2=1), the orientation of C 2H 2(X～ 1Σ + g, ν″ 2=1,J″ =4,7,8,9,10,11,12,13) is measured for the first time. The decay rate constants and transfer of the orientation from the initial excited level to neighboring rotational states have been extracted.