Cross Sections for Formation of H(2p) and H(2s) Atoms in H+-Alkali-Atom Charge Transfer Collisions

Partial cross sections σ L and σ m for respective formation of H(2p) and H(2s) atoms in charge-transfer collisions of H 1 with Cs, Rb, K and Na atoms have been measured over the energy range from 0.06 to 5.0 keV. The measurement of σ L was made by the use of crossed-beam method together with detection of H(2p) atoms by Lyman-α photons emitted in spontaneous decay of those atoms. The measurement of σ m was made by the use of beam-target-cell method together with detection of H(2s) atoms by Lyman-α photons emitted when an electric field was applied on them. Almost all of cross-section curves obtained show oscillatory structures arising from secondary effects. The aspect of the structure changes remarkably with target atom, suggesting that the long-range sharing process between charge-exchange channels in Cs and Rb cases is replaced by a different secondary effect in K and Na cases.