Branching ratio between resonant and non-resonant ionization of xenon evaluated from photoelectron angular distributions

Photoelectron imaging of xenon gases ionized with a femtosecond 388 nm pulse reveals three ionization processes: resonant and non-resonant multi-photon ionization and autoionization. The relative yield of the first two was evaluated from the deconvolution of their angular distribution for the specific electron energy, which includes the electron production via the 3hv-5p(5)(P-2(1/2)degrees)6s resonance. The non-resonant process gains in importance with increasing laser intensity and accounts for 50% of the ionization yield at 30 TW cm(-2).