| 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 (λ=1.5 μm), we quantitatively determined both (i) the first charge state saturation intensities and (ii) the absolute ionization rates for intensities ranging from threshold up to 3×1014 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. |
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