Excitation of Li(2p) and He(2p) in collisions of Li+with He at energies below 4.2 keV

Abstract

Radiative collision processes between Li+ and He have been studied in the projectile energy range from 0.45 to 4.2 keV. The total cross sections for Li(2p2P) and He(2p1P) excitations show the oscillations in antiphase with each other. A polarisation measurement was done for the 2p to 2s transition of Li; the degree of the polarisation is found to be relatively small in the energy range studied. The partial excitation cross sections for the magnetic sub-levels 2p0 and 2p+or-1 of Li(2p2P) are obtained. On the basis of the sudden approximation, the kinematic effect in the polarisation measurement is discussed in detail.