Multiple Ionization of Atoms in Intense Laser Fields

A new ultrahigh vacuum-compatible ( 10 11 mbar) "reaction microscope" was built to investigate multiple ionization of atoms and molecules in ultra-short (23 fs), intense laser pulses (1014 1016 W/cm2, 795 nm) . In first experiments ion momentum distributions for single and double ionization of noble gas atoms in the nonsequential and sequential intensity regime were measured using linearly polarized laser pulses. The apparatus is currently improved to perform measurements under even lower residual gas pressures (< 10 13 mbar). Furthermore, the new apparatus is ideally suited for future studies on dissociation and Coulomb explosion of molecules.