FIRST AND SECOND ORDER CORRECTIONS TO THE DIPOLE APPROXIMATION OBSERVED IN NEON BELOW 1000 EV O. Hemmers, P. Glans, H. Wang, S.B. Whitfield, D.W. Lindle, R. Wehlitz,* I.A. Sellin,* A. Derevianko,# W.R. Johnson# Department of Chemistry, University of Nevada, Las Vegas, Nevada, USA *Department of Physics and Astronomy, University of Tennessee, Tennessee, USA # Department of Physics, University of Notre Dame, Notre Dame, Indiana, USA Strong deviations in angular distributions of Ne 2s and 2p photoemission from the dipole approximation have been observed at photon energies below 1000 eV. In the first-order correction two new parameters, arise from dipole-quadrupole interferences. Second-order corrections are characterized by four parameters. We found that first and second-order corrections are necessary to satisfactory describe the Ne n = 2 angular distributions.