Photoelectron angular distributions from rotationally resolved autoionizing states of N-2

摘要

The single-photon, photoelectron-photoion coincidence spectrum of N-2 has been recorded at high (similar to 1.5 cm(-1)) resolution in the region between the (N2+X2)Sigma(+)(g), nu(+) = 0 and 1 ionization thresholds by using a double-imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the (N2+X2)Sigma(+)(g) ground state, and electronically autoionizing states converging to the N(2)(+)A(2)Pi and B-2 Sigma(+)(u) states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. A simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, beta, and the results are in reasonably good agreement with experiment. Published by AIP Publishing.