Angular distribution of photo electrons from above-threshold-ionization (ATI) of xenon by 532 nm, 355 nm and 266 nm radiation

A time-of-flight electron energy spectrometer has been used to measure the angular distributions of photoelectrons emitted after the absorption of up to four excess photons above the ionization threshold of Xenon at 532 nm. For shorter wavelength less efficient ATI is observed. The shape of the angular distributions and the branching ratios for the two ionic fine structure states Xe⁺(² P _3/2) and Xe⁺(² P _1/2) may be plausibly attributed to the influence of excited states of the atom.