Core Level Excitation and Relaxation in Molecules

纽约州立大学石溪分校的大卫·m·汉森在实验物理化学项目的支持下，利用国家同步加速器光源（NSLS）的x射线辐射，选择性地激发气相分子中的核心电子，然后研究核心-空穴衰变。他将确定这种选择性是如何在衰变过程中保持的，确定所涉及的激发态，并研究衰变过程中分子结构的依赖性。此外，还将研究核心电子激发后碎片化的机制和动力学，以及最终态能量分布及其与势能面的关系。要研究的过程在发生在空间、行星大气和原子反应堆中的化学反应中起着关键作用。例如，x射线吸收光谱在天文学中被用来提供关于宇宙的信息。核-电子激发和电离以及核-空穴衰变过程被用来研究非均相催化，并通过电子、x射线显微镜和光刻技术进行。这些知识提供的洞察力可能最终产生新的材料。

David M. Hanson of the State University of New York-Stony Brook is supported by the Experimental Physical Chemistry Program to selectively excite, using x-ray radiation from the National Synchrotron Light Source (NSLS), core electrons in gas phase molecules, and then study the core-hole decay. He will determine how this selectivity is preserved during decay, identify the excited states involved, and look at the molecular structure dependence of the decay processes. In addition, the mechanisms and dynamics of fragmentation after core electron excitation will be investigated, as will the final state energy distribution and its relationship to the potential energy surface. The processes to be studied play a key role in the chemistry occurring in space, in planetary atmospheres, and in atomic reactors. For example, x-ray absorption spectra are used in astronomy to provide information about the universe. Core-electron excitation and ionization and core-hole decay processes are used to study heterogeneous catalysis, and occur with the techniques of electron- and x-ray microscopy and lithography. Insight provided by this knowledge may eventually produce novel materials.