Absolute cross sections for charge exchange, ionization, stripping, and excitation in K + -He collisions were measured in the ion energy range 0.7-10 keV. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. The increase of the excitation probability of inelastic channels with the angle of scattering is revealed. An exceptionally highly excited state of He is observed and a peculiarity for the excitation function of the resonance line is explained. The intensity ratio for the excitation of the K II λ = 60.1 nm and λ = 61.2 nm lines is 5:1, which indicates the high probability for excitation of the singlet resonance level 1 P 1 compared to the triplet level 3 P 1 . The similarity of the population of the 4p state of the potassium ion and atom as well as the anomalously small values of the excitation cross sections are explained.

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Absolute emission cross sections for the excitation atomic and ionic lines of nitrogen are measured in the VUV region of 50 to 130 nm in the He+ projectile energy range 1-10 keV. Excitation of the intense lines are caused by formation of core-excited intermediate molecular states of N2+* in the charge exchange processes. In particular the most intense line N I (120.0 nm) can be excited by formation of a 2s sigma g hole in the ground state of the N2 molecule. This intermediate one-hole molecular state of N+2 can be formed by configuration interaction with 2 Sigma +g core-excited molecular Rydberg states.

The absolute cross sections for the e−N2 and p−N2 collisions for the first negative B 2 Σ + u −X 2 Σ + g and Meinel A 2 Πu−X 2 Σ + g bands have been measured in the energy region of 400−1500 eV for electrons and 0.4−10 keV for protons, respectively. Measurements are performed in the visible spectral region of 400-800 nm by an optical spectroscopy method. The ratio of the cross sections of the Meinel band system to the cross section of the first negative band system (0, 0) does not depend on the incident electron energy. The population of vibrational levels corresponding to A 2 Πu states are consistent with Franck-Condon principle. The ratio of the cross sections of (4, 1) to (3, 0) bands, and (5, 2) to (3, 0) bands exhibits slight dependence on the proton energy. The theoretical estimation within the quasimolecular approximation provides a reasonable description of the total cross section for the first negative band.