Velocity map imaging of atomic and molecular processes at the free electron laser in Hamburg (FLASH)

Velocity map imaging was implemented at the free electron laser in Hamburg to image atomic and molecular photoionization processes at a photon energy of 45.55 eV. High quality momentum distributions were recorded for a range of rare gases (He, Ne, Ar, Kr and Xe) and small molecules (H₂, D₂, O₂, N₂, CO₂). This proof-of-principle experiment illustrates the potential for using velocity map imaging in order to study non-linear ionization and/or dissociation processes.