Molecular Frame Photoemission： Probe of the Photoionization Dynamics for Molecules in the Gas Phase

作     者：D. Dowek Y. J. Picard P. Billaud C. Elkharrat J. C. Houver 

作者机构：Université Paris-Sud 11 UMR 8625 Laboratoire des Collisions Atomiques et Moléculaires Bat. 351 Université Paris-Sud 91405 Orsay France CNRS UMR 8625 Laboratoire des Collisions Atomiques et Moléculaires Bat. 351 Université Paris-5ud 91405 Orsay France 

出 版 物：《Chinese Journal of Chemical Physics》 (化学物理学报（英文）)

年 卷 期：2009年第22卷第2期

页      面：178-186页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0703[理学-化学] 0702[理学-物理学] 

基　　金：the support of S. Damoy engineer at the LCAM 

主　　题：Dissociative photoionization Molecular frame photoemission Circular dichroism in photoemission Autoionization dynamics Synchrotron radiation Vector correlation 

摘      要：Molecular frame photoemission is a very sensitive probe of the photoionization （PI） dynamics of molecules. This paper reports a comparative study of non-resonant and resonant photoionization of D2 induced by VUV circularly polarized synchrotron radiation at SOLEIL at the level of the molecular frame photoelectron angular distributions （MFPADs）. We use the vector correlation method which combines imaging and time-of-flight resolved electron-ion coincidence techniques, and a generalized formalism for the expression of the Ⅰ（χ, θe, Фe） MFPADs, where χ is the orientation of the molecular axis with respect to the light quantization axis and （θe, Фe） the electron emission direction in the molecular frame. Selected MFPADs for a molecule aligned parallel or perpendicular to linearly polarized light, or perpendicular to the propagation axis of circularly polarized light, are presented for dissociative photoionization （DPI） of D2 at two photon excitation energies, hv=19 eV, where direct PI is the only channel opened, and hv=32.5 eV, i.e. in the region involving resonant excitation of Q1 and Q2 doubly excited state series. We discuss in particular the properties of the circular dichroism characterizing photoemission in the molecular frame for direct and resonant PI. In the latter case, a remarkable behavior is observed which may be attributed to the interference occurring between undistinguishable autoionization decay channels.