Polarization-correlation Stokes parameters for the quadrupole 2p6-2p53p J=2 transitions in neon

Abstract

First calculations of the polarization-correlation Stokes parameters Pi (i=1,2,3,4) for the quadrupole excitations by electron impact in heavy inert gases are carried out taking the 2p53p J=2 states of neon as an example. The distorted-wave Born approximation and the multichannel diffraction approximation are used and the sensitivity of the Pi parameters to different couplings is studied. The indirect dipole couplings via the resonance 2p53s J=1 levels cause a drastic rotation of the excitation amplitudes in the complex plane and strongly affect the Stokes parameters. The results are compared with recent measurements. The excitation cross sections are briefly discussed.