Alignment of Ar+ ions produced after resonant auger decay of Ar*2p(5) 3d resonances

Abstract

Fluorescence spectra have been recorded in the wavelength region 300 nm less than or equal to lambda(fluo) less than or equal to 500 nm after resonant 2p --> 3d excitation of atomic Ar using monochromatic synchrotron light. The radiative emission is characterized by strong transitions from Ar+ 3p(4) (S-1, D-1, P-3) nl ionic states. It is mainly assigned to processes of the type 3p(4) 4d --> 3p(4) 4p and 3p(4) 4p --> 3p(4) 4s. In addition, we have analyzed the degree of polarization of the fluorescence lines and we have determined the alignment of the Ar+ ions, which are produced after the resonant Auger decay. In comparison to investigations based on photoelectron spectroscopy, the spectral analysis of the fluorescence provides complementary information about the electronic relaxation during the resonant Auger process and, in particular, it allows one to examine directly the remaining ion.