Strong-field multiple ionization of krypton

We have investigated the multiple ion yields of Kr, up to Kr4+ as a function of the field intensity, that are measured using a linearly polarized short-pulsed Ti:sapphire laser of lambda = 800 nm in the range of up to mid-10(15) W/cm(2), within an S-matrix model for nonsequential multiple ionization. Experimental data and theoretical predictions are in good agreement and the influence of different nonsequential channels on the measured ion yields are analyzed.