Anisotropy and relaxation dynamics in core-excited small molecules

(1)为了研究核心激发分子的电子衰变和解离动力学，我们开发了一种装置，该装置允许我们进行角分辨光电子/俄歇电子能谱、角分辨离子能谱和能量选择电子-能量选择离子符合。(2)我们在筑波的光子工厂进行了一系列实验，并阐明了核心激发分子的极化/取向如何影响电子衰变和解离动力学。具体地说，我们发现：（1）对于D_<3h>平面分子BF_3和BC_<l3>，分子的形变是以一种特定的核激发态的方式发生的，并影响随后的分子解离。（2）在高分辨共振俄歇谱中可以检测到与核激发态分子形变有关的核运动。（3）F是高度对称分子如CF_4和SF_的核激发4）BF_3中的B 1 s，PF_3和PF_5中的P 2 p，SF_6中的S2 p受形状共振的影响很大。5）PF_5中P2p激发后，由于P2p核-空穴衰变使各向异性消失，离子碎裂几乎是各向同性的。

(1) Aiming to investigate the electronic decay and dissociation dynamics of core excited molecules, we have developed an apparatus that allows us to perform angle-resolved photoelectron/Auger-electron spectroscopy, angle-resolved ion spectroscopy, and energy-selected electron - energy selected ion coincidence.(2) We have carried out a series of experiments at the photon factory in Tsukuba and elucidated how the polarization/orientation of the core-excited molecule affects the electronic decay and dissociation dynamics. Specifically, we found :1) In case of D_<3h> planar molecules BF_3 and BC_<l3>, the molecular deformation occurs in a way that is characteristic to a specific core-excited state and influences the subsequent molecular dissociation.2) The nuclear motion related to the molecular deformation in the core excited state can be detected in the high-resolution resonant Auger spectrum.3) The F is core excitation of highly symmetric molecules such as CF_4 and SF_6 induces symmetry breaking due to vibronic coupling and results in anisotropic molecular fragmentation.4) The anisotropy of the photoelectron emission from B 1s in BF_3, P 2p in PF_3 and PF_5, and S 2p in SF_6 is strongly influenced by the shape resonances.5) Ionic fragmentation is nearly isotropic after P 2p excitation in PF_5 due to loss of the anisotropy via the P 2p core-hole decay.