Electron-impact excitation of the doubly charged potassium ion from the ground atomic state

The results of a study of the process of double ionization with simultaneous electron-impact excitation of the potassium atom from the ground state are presented. Data have been obtained on the excitation cross sections of sixteen transitions in the 2500--3500-A spectral region. The measurements involved the use of the method of intersecting beams. Absolute values of the excitation cross sections of seven levels, a typical excitation function, are given. On the basis of the data obtained, the probabilities of radiative transitions are determined from the level lifetimes reported in the literature