Excitation cross sections for odd triplet levels of LaII in e-La collisions

The method of extended crossing beams with the recording of an optical sign al from an intersection region is used to study the excitation of a singly charged lanthanum ion. The process in question is accomplished in a single collision event between a lanthanum atom and an electron, i.e., as an excit ation process with simultaneous single ionization. Excitation cross section s for 105 spectral lines arising upon transitions from odd triplet levels o f LaII are measured. Also recorded are 16 optical excitation functions for 85 lines. The results obtained are used to calculate the cross sections for excitation of the energy levels and the contribution of cascade transition s to their population. (C) 2000 MAIK "Nauka/Interperiodica".