Projectile excitation in the collision of Arsup(q+) (q = 1, 2 and 3) with He and Ne

Cross sections for radiative emission from Ar II (3p44s2P), Ar II (3p43d 2D), Ar II (3s3p62S), Ar III (3s3p51P) and Ar III (3s3p53P) projectile states have been measured for Arsup(q+) (q = 1, 2 and 3) ions colliding with He and Ne at impact energies between 15 and 400 keV. The experimental results are explained qualitatively by considering the MO correlation diagrams and potential energy state diagrams. It is often found that the cross section for excitation decreases with the increase of the number of intermediate transitions required in order to reach the excited state. (author)