Dissociation Dynamics of Superexcited Molecukes studied using the Advantage of Synchrotron Radiation for Continuous Wavelength, Linear Polarization, and Pulsed Time-Structure

基于本研究者在辐射化学中首次证明的超激发分子动力学行为的一般性认识，以及我们以前用低能电子束和vuv-同步辐射进行的解离研究所进一步证实的认识，本研究拟通过以下方法对超激发态的电子性质及其离解动力学进行详细的研究：结合同步辐射连续波长的特点，提出了同步辐射线偏振和脉冲时间结构的概念，在1991-1993年的研究期间，我们根据我们的建议进行了以下研究：(1)本文用快速响应延迟符合时间分辨荧光测量方法，测量了H_2中性光解离过程中H原子的角动量布居。更高分辨率 ...更多信息 为了获得更多的状态分辨信息，还进行了分辨测量。对D_2分子也进行了测量。通过测量激发态H原子碎片相对于同步辐射线偏振矢量的荧光强度，得到了超激发态H_2的对称性信息。(2)测量了CH_4，CCl_4，SiF_4和SiCl_4等多原子分子的光吸收、光电离和中性光解离的绝对截面，得到了给定光子能量在这些过程中分配的详细信息。(3)本文观察和测量了超激发O_2、N_2和N_2O解离产生的中性碎片的真空紫外荧光随SR波长的变化。进一步对荧光进行了色散处理，得到了二维荧光激发谱，它是同步辐射波长和荧光波长的激发函数。这些激发谱给出了中性解离过程中超激发态的详细结构信息。少

On the basis of the general understanding on the dynamic behavior of superexcited molecules, which was demonstrated by the present investigator for the first time in radiation chemistry and further carified by our previous dissociation studies using a low energy electron beam and a vuv-synchrotoron radiation, the present investigation has been proposed to perform detailed studies on the electronic property of superexcited states and their sissociation dynamics by advancing the synchrotron radiation (SR) for linear polarization and pulsed time-structure in combination with its continuous wavelength character.In the term of investigation, 1991-1993, we have carried out the following studies in accordance with our proposal.(1) Measurements of the angular momentum population of excited H atoms produced in the neutral-photodissociation of H_2 via superexcited state have been made by establishing a fast-response delayd coincidence method for time-resolved fluorescence measurement. Higher res … More olution measurements have also been performed in order to obtain further more state resolved information. The measurements have also been made for D_2 moleculars. We have also obtained the information on the symmetry of the superexcited H_2 by measuring the fluorescence intensity from excited H fragments relative to linear polarization vector of synchrotron radiation.(2) Absolute cross sections for photoabsorption, photoionization, and neutral photodissociation of polyatomic molecules, such as CH_4, CCl_4, SiF_4, and SiCl_4 have been measured to obtain the detailed information on partitioning of given photon energy into these processes.(3) vuv-fluorescence from neutral fragments produced in the dissociation of superexcited O_2, N_2, and N_2O has been observed and measured as a function of SR wavelength. The fluorescence has further been dispersed and measured as two dimensional fluorescence excitation spectra, which are the excitation function of both synchrotron radiation wavelength and fluorescence wavelength. Thease excitation spectra have given the detailed information on the potential structures of superexcited states, through which neutral dissociation proceeds. Less