SHORT-PULSE MPI OF XENON - THE P-2(1 2) IONIZATION CHANNEL/

We present photoelectron spectra measured by 'short' pulse (tau(p) sim ilar or equal to 0.7 ps) MPI of xenon at 526.5 nm excitation wavelengt h in the intensity range 10(13) to 3 x 10(14) W cm(-2). Ionization int o Xe+ P-2(3/2) and P-2(1/2) channels is observed and resonance structu res are found in both ionization channels. They are induced by the AC Stark shift of bound Xe states within the light pulse which brings the m into transient n-photon resonance with the Xe ground state. The reso nant states are tentatively identified as d- and s-angular momentum st ates having AC Stark shifts which differ from the shift of the xenon i onization threshold. In the high-intensity limit, ionization into the Xe+ P-2(1/2) channel is completely suppressed.