Time-Resolved ESCA: a Novel Probe for Chemical Dynamics

Abstract

Abstract Electron spectroscopy for chemical analysis (ESCA) is a well established tool for quantitative studies of the composition and the chemical environment of molecular systems. Recent developments in the generation and utilization of ultrashort X-ray pulses now add the dimension of time to this technique and will expand the possibilities of femtochemistry in terms of chemical selectivity, quality of information, and temporal resolution. The properties and capabilities of various X-ray pulse sources are discussed, along with their prospects for dynamical studies. Examples of time-resolved electron spectroscopy are presented in the femtosecond (1 fs = 10−15 s) as well as the attosecond (1 as = 10−18 s) regime, the latter marking the current ultimate limit for the time-resolution in pump-probe experiments.