Excitation of 1s4/levels of He atoms by (10-30keV) He atoms impact

摘要

He-He collisions have been investigated in the intermediate-energy range, where the relative velocity of the Helium atoms is on the order of the Bohr velocity. By measuring the fluorescence-light intensity of the spectral line lambda(4(3) D-2 P-3) = 447 nm as a function of an electric field F-z applied parallel and antiparallel to the projectile beam, the excitation mechanism has been analyzed. The experimental results are in agreement with the assumption that two electrons are lifted simultaneously on the saddle of the two-center potential of two He+ ions according to the Paul-trap model.