UV and soft x-ray photodynamics of molecular ions

Introduction

The imaging of individual molecular fragmentation events with fast ion beams has recently been successfully implemented at the new Free Electron Laser light source FLASH  (DESY, Hamburg, Germany). Molecular ions offer rich photodynamics on their excited, often coupled, potential surfaces when they are broken up in parts by ultraviolet or soft x-ray radiation. Experimental data on the cross sections and product channels resulting from this photodynamics are extremely scarce for ionized molecules. Moreover, the fast-beam fragmentation imaging technique uniquely provides access to the complete fragmentation dynamics, including the neutral fragments often remaining unobserved in photofragmentation studies of polyatomic molecules with targets at rest using standard techniques.