Postcollision interaction upon electron excitation of 4sns1S0, 3S1 and 4snd1D2, 3DJ levels of zinc atom

The optical excitation functions (OEFs) for four series of spectral lines of the Zn atom at the transitions 4sn ₁ s ¹ S ₀ → 4s4p ¹ P ₁^∘ (n ₁ = 6–10), 4sn ₂ s ³ S ₁ → 4s4p ³ P ₂^∘ (n ₂ = 6−8), 4sn ₃ d ¹ D ₂ → 4s4p ¹ P ₁^∘ (n ₃ = 4−6), 4sn ₄ d ³ D _{1, 2, 3} → 4s4p ³ P ₂^∘ (n ₄ = 4−7) excited by a monoenergetic (0.04–0.08 eV) electron beam with energies from the excitation threshold to 18–19 eV are measured. In the energy dependences of the excitation cross sections, the effect of post-collision interaction of slow (scattered) and fast (emitted after the autoionization state decay) electrons is observed and described. This interaction leads to the capture of a slow electron into the listed discrete levels and the appearance of maxima in the excitation functions. The energies of the maxima are used to determine the energies and widths of single autoionization states or their groups by approximate formulas of the classical approach. The autoionization levels of the zinc atom responsible for the maxima observed are determined. Possible transfer of the orbital angular momentum between electrons is analyzed.