Soft X-ray Molecular Spectroscopy: Dissecting the Continuum

在这个由化学部实验物理化学计划支持的项目中，Poliakoff将使用软X射线分子光谱学来识别和表征光电子喷射过程中保持其分子特性远离阈值的方面。电子激发的光离子将使用可调谐的同步辐射产生，并将通过它们的分散荧光来研究它们的动力学。这些研究的独特之处在于，所探测的动能范围扩展到数百eV的电离连续体，在电离连续体中，电子喷射的分子特征仍然存在。在宽广的光电离能范围内，振动和转动能沉积到分子光离子中将被确定。早期对简单分子的实验将扩展到研究小的多原子分子。这些实验的结果将为利用光致电离的实验提供一个有用的数据库，并将提供对基本散射现象的见解，从而有助于分子散射理论的继续发展。在这个项目中进行的实验中，当分子在高能光的影响下解离时，电子的运动将与原子核的运动相关联。这些研究中使用的光将部分来自路易斯安那州立大学的同步辐射光源。在这些研究中获得的数据是其他技术无法获取的，将用于指导和形成这些过程的理论模型。这个项目中研究的一些过程与理解材料的X射线处理过程中涉及的物理和化学反应有关。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Poliakoff will identify and characterize aspects of the photoelectron ejection process which retain their molecular character far from threshold using soft X-ray molecular spectroscopy. Electronically excited photoions will be created using tunable synchrotron radiation, and their dynamics will be investigated via their dispersed fluorescence. These studies are unique in that the range of kinetic energies probed extends hundreds of eV into the ionization continuum, where the molecular character of the electron ejection still persists. Vibrational and rotational energy deposition into molecular photoions over a broad range of photoionization energies will be determined. Earlier experiments on simple molecules will be extended to examine small polyatomic molecules. The results of these experiments will provide a useful database for experiments employing photoionization and will furnish insights into fundamental scattering phenomena, thereby aiding the continued development of molecular scattering theory. In the experiments performed in this project, the motions that electrons make when molecules dissociate under the influence of high-energy light will be correlated with the motions of the nuclei. The light used in these studies will come in part from a synchrotron radiation source at Louisiana State University. The data acquired in these studies is inaccessible by other techniques and will be used to guide and shape theoretical models for these processes. Some of the processes studied in this project are relevant to understanding the physical and chemical reactions involved in the X-ray processing of materials.