Real-time observation of ultrafast ionization and fragmentation of mercury clusters

Abstract

We report on time-resolved multiphoton ionization and fragmentation dynamics of free Hg n -clusters (n≤110) with femtosecond laser pulses. Already at laser intensities of 1011 W/cm2 we observe prompt formation of singly, doubly, and triply charged Hg n clusters. In pump-probe experiments short-time (0–5 ps) oscillatory modulations of the transient Hg n + and Hg n 2+ signals are observed which indicate an intermediate state dynamics common to all observed cluster sizes and charge states. Long-time (0–200 ps) transient ionization signals show caged dissociation and recombination chromophore dynamics.