title: Absolute ionization rates of multielectron transition metal atoms in strong infrared laser fields.
abstract: We report on nonresonant strong field ionization of the multielectron transition metal atoms V, Nb, Ta, Ni, and Pd. Operating in the adiabatic regime (lambda = 1.5 microm), we quantitatively determined both (i) the first charge state saturation intensities and (ii) the absolute ionization rates for intensities ranging from threshold up to 3 x 10(14) W/cm2. We observed a dramatic suppression of ionization relative to single active electron approximation expectations. We suggest that this derives from dynamic polarization or screening effects within the multielectron atom, stressing a need for many-body theories of strong field ionization.
authors.affiliation: Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Smits
authors.forename: C A
authors.initials: CA
authors.lastname: de Lange
authors.forename: Albert
authors.initials: A
authors.lastname: Stolow
authors.forename: D M
authors.initials: DM
authors.lastname: Rayner