L2,3M4,5M4,5principal and satellite Auger spectra of free copper atoms

The atomic $L_{2,3}{M}_{4,5}{M}_{4,5}$ Auger electron spectrum of Cu has been measured and analyzed in detail. Besides determination of the kinetic energies and relative intensities of the lines in the Auger spectrum, the free-atom binding energies $E_B\left(2\mathrm{}{p}_{\frac{3}{2}}\right)=939.85\mathrm{}\pm 0.15$ eV and $E_B\left(2\mathrm{}{p}_{\frac{1}{2}}\right)=959.45\mathrm{}\pm 0.15$ eV are also obtained. The comparison with corresponding solid-state results gives 2.5 eV for the solid-state binding-energy shift of $2p$ levels and 13.2 eV for the $L_{2,3}{M}_{4,5}{M}_{4,5}$ Auger shift. $L_{3}M-M_{4,5}{M}_{4,5}M$ satellite Auger lines arising from primary ionization in $L_1$ shell are seen clearly in the measured spectrum. They have been discussed and compared with the corresponding solid-state spectra. After correction for the $L_{2}M-M_{4,5}{M}_{4,5}M$ satellite spectrum, which overlaps the $L_3{M}_{4,5}{M}_{4,5}$ spectrum, the intensity ratio between $L_3$ and $L_2$ Auger groups was found to obey the statistical ratio quite well in contradiction to solid-state measurements, where $L_2{L}_3{M}_{4,5}$ Coster-Kronig transitions are energetically possible and modify this intensity ratio.