Excitation of He—41 D-substates by He+- and Ne+-projectiles investigated by level-crossing techniques

Collisions of He⁺- and Ne⁺-projectiles with He at impact energies between 90 keV and 800 keV were investigated. Relative excitation cross sections for magnetic sublevels of He—4¹ D were determined using level-crossing techniques. Absolute excitation cross sections σ _m of the Zeeman-sublevels are given using He—4¹ D cross sections from earlier measurements. The results show strong variations of the cross sections σ₀ and σ_±1 with a quasi-oscillatory behaviour. σ_±2 is much smaller than σ₀ and σ_±1.