Excitation of the copper atom by electron impact

The method of extended crossing beams was used to investigate inelastic collisions of copper atoms with slow monokinetic electrons. The excitation cross sections of 160 spectral lines of the copper atom, located in the range 202 – 810 nm, were determined at the exciting electron energy 50 eV. Seventy-nine optical excitation functions were found in the electron energy range from the threshold to 250 eV. For the spectral series 4p²P⁰ – ns²S and nd²D the dependences of the cross sections on the principal quantum number of the upper level were of the power-law type, but strong perturbations were observed for the 4s^2 2 D – np²P⁰ series. The results obtained were used to calculate the excitation cross sections of 19 energy levels of the copper atom. The results were compared with those obtained by other authors.