束—气条件下He（2^3S）与CH3Cl及CH3I的传能研究

The Study of Energy Transfer Reaction form He(2~3S) to CH_3Cl and CH_3I in a Beam-gas Condition

在束-气条件下，通过检测产物的化学发光，研究了亚稳电子激发态He（23S）原子与CH3Cl、CH3I传能反应.采用参比反应的方法，测得了由上述反应产生的主要碎片CH（A2△）、CH（B2∑-）、CH（C2∑+）和H*形成速率常数．通过对测得的CH（A2△－X2∏r）和CH（B2∑-－X2∏r）色散谱进行计算机模拟，获得了初生态的CH（A2△，v＝0－2）和CH（B2∑-，v＝0态）的振动-转动布居，实验结果表明，CH（A2△，v＝0）态的转动布居是呈双Boltzman分布的，并且反应的可资用能大部分将转变成产物的平动能．根据实验结果和反应阈能的分析，本文对He（23S）与CH3Cl／CH3I传能反应机理进行了探讨。

The energy transfer reactios from He(23S) to CH3Cl and CH3I have been studied in a beam-gas condition by observing the emission of the excited state products. The formation rate constants of CH(A), CH(B) and CH(C) produced by He(23S) with CH3Cl or CH3I were determined. The nascent rovibrational distrbution of CH(A2△, v＇ = 0 - 2)and CH(B2 ∑-,V' = 0) from above reactions were obtained by a computer simulation of CH(A - X, B - X) emission. The experimental results showed that the major of the reaction available energies is deposited into the translation energies of the products. The mechanism of the energy transfer reactions from He(23S) to CH3Cl and CH3I were also discussed.