Photoelectron angular distributions from rotationally state-selected NH3(B1E′′): dependence on ion rotational state and polarization geometry

Abstract

By using high-resolution photoelectron velocity map imaging and a pump–probe ionization scheme we are able to demonstrate that photoelectron angular distributions from ammonia depend sensitively on the neutral rotational level that is ionized, and on the rotational level of the ion that is formed. We use this sensitivity to fully determine the photoionization dynamics giving rise to the observed photoelectron angular distributions and rotational branching ratios. In addition, we observe the dependence of the photoelectron angular distributions on initially prepared alignment, by varying the relative polarizations of pump and probe. This dependence can be used to corroborate the determined photoionization dynamics, and also provides a demonstration that tomographic reconstruction can be used to recreate three-dimensional photoelectron distributions in non-cylindrically symmetric situations.