Electron-Impact Molecular Excitation and Dissociation as studied by the Infrared Emission Spectroscopy

为了扩大我们用UV-Vis发射光谱研究电子碰撞激发和解离过程的范围，建议使用红外发射光谱。我们的主要研究结果如下：1)设计和建造了一台测量电子-电子碰撞过程中产生的红外辐射的新仪器。2)测量了e-H_2碰撞产生的受激氢原子的帕森线的发射谱，并测定了它在20-1000 eV电子能量范围内的发射截面。3)由Balmer和Pschen谱线的发射截面确定了激发态氢原子的方位量子数分布(n=4)。与理论预期相反，4f激发的氢原子具有正的发射截面。4)讨论了4f原子的形成机制。解离过程中较大核间距处的曲线交叉将是最合理的解释。5)在UV-Vis电子能谱中已经测定了几个碎片物种的振动和转动分布，但它们的红外光谱测定还没有完成，还有待于以后的测量。阐明了H_2O、C_2H_2、C_2H_4和HCI的解离动力学。

In order to extend our investigations on the electron-impact excitation and dissociation processes using the UV-VIS emission spectroscopy, the use of the infrared emission spectroscopy has been proposed. The major results of our investigations are as follows.1) A new instrument for the measurement of the infrared emission produced in electron-motlcule collision processes has been designed and constructed.2) The emission spectra of the Paschen line of the excited hydrogen atom produced in e-H_2 collisions have been measured, and its emission cross sections have been determined for electron energies of 20-1000 eV.3) The azimuthal quantum number distribution of the excited hydrogen atom (n=4) has been determined from the emission cross sections of the Balmer and Pschen lines. Contrary to the theoretical expectation, there is a positive emission cross section of the 4f excited hydrogen atom.4) The mechanism for the formation of the 4f atom has been discussed. A curve crossing at a larger nuclear distance in the dissociation process would be the most plausible explanation.5) The vibrational and rotational distributions of several fragment species have been determined in the UV-VIS emissdion spectroscopy.However, their IR determination has not been completed, and is to be measured in future.6) Doppler profile measurements have been successfully carried out. The dissociation dynamics of H_2O, C_2H_2, C_2H_4 and HCI have been clarified.