High-resolution angle-resolved measurements in atoms and molecules using advanced photoelectron spectroscopy at the ALS

Abstract

A two-dimensional photoelectron imaging technique using time-of-flight spectrometry and a high-resolution SES-200 electron energy analyzer have been used with photons from the atomic and molecular undulator beamline of the Advanced Light Source to study the structure and dynamics of atoms and molecules. The analyzers are rotatable around the direction of the photon beam, allowing angular-dependent studies to be performed. Results on the photoexcitation and decay mechanisms of doubly excited resonances in neon illustrate the importance of spin-orbit effects for such a light atom, since significant breakdown of LS-coupling was measured for such a light atom . Also, fully vibrationally resolved Auger electron spectra measured under Resonant Raman conditions following the C 1s→π* excitation in a diatomic molecule, CO, is presented which allows us to probe the core excited states, their excitation and de-excitation dynamics with unprecedented resolution.