High resolution angle-resolved measurements of Auger emission from the photo-excited 1s⁻¹3p state of Ne

We present measurements of the resonant Auger electron emission at an electron kinetic energy of ~810 eV in the Ne atom following 1s → 3p excitation at an excitation photon energy of 867.12 eV, with a photon band pass of 60-68 meV, an electron energy resolution of 13 meV, and the Doppler width due to thermal motion of the sample Ne atoms of 79 meV. Under these conditions, the overall resolution of 100-105 meV (FWHM) is much smaller than the natural width, 250 meV, of the Ne 1s hole state, and the resonant Auger final states 2p-2(1D2)3p (or 4p) 2P, 2D, 2F are completely (or partially) resolved. The obtained β values and branching ratios are in good agreement with first principles calculations by means of the multi-configuration Dirac-Fock methods within the framework of the two-step model.