Excitation of LaII singlet levels in collisions of electrons with lanthanum atoms

The method of extended crossing beams with detection of the optical signal from the intersection region is used to investigate the excitation of Lan: spectral lines in collisions of electrons with lanthanum atoms. The investigation results are used to calculate the total excitation cross sections of 17 singlet levels with the electron energy of 30 eV. The contribution made: by cascade transitions and direct excitation cross sections is determined for seven odd-parity levels.