Multiple ionization and fragmentation dynamics of molecular iodine studied in IR–XUV pump–probe experiments

Abstract

The ionization and fragmentation dynamics of iodine molecules (I₂) are traced using very intense (∼10¹⁴ W cm⁻²) ultra-short (∼60 fs) light pulses with 87 eV photons of the Free-electron LASer at Hamburg (FLASH) in combination with a synchronized femtosecond optical laser. Within a pump–probe scheme the IR pulse initiates a molecular fragmentation and then, after an adjustable time delay, the system is exposed to an intense FEL pulse. This way we follow the creation of highly-charged molecular fragments as a function of time, and probe the dynamics of multi-photon absorption during the transition from a molecule to individual atoms.