2-DIMENSIONAL STATE-RESOLVED IMAGING AFTER UV-LASER INDUCED DESORPTION - NO/NIO(111)

We present an experimental set-up which can image state selectivity the two-dimensional angular distribution of neutrals or ions desorbing from a surface after UV-laser excitation together with the velocity flux distribution of a single rovibronic state in a single experiment. The method combines a state selective detection method like resonance enhanced multiphoton ionization (REMPI) with an imaging technique. This method is particularly fast in comparison to other one-dimensional methods and ideal for systems where the substrate is modified via irradiation with laser light. The normally used set-up in state resolved laser desorption experiments for two-dimensional imaging [1] is limited to look at the azimuthal distribution. We report on results of the determination of angular distributions of NO desorbing from NiO(111) after excitation with 193 nm (6.4 eV) laser light. The velocity flux distributions also obtained are compared to former one-dimensional experiments performed in our laboratory.