Autoionising levels in argon excited by low-energy heavy-ion impact

Energy spectra of 5-20 eV electrons ejected from autoionised states in argon, excited in 1-15 keV He + , He, Li + , Li, Ne + , Ne, Na + , Na, K-Ar and Ar + -He. Ne collisions have been measured. Rich spectral features from the autoionising configurations KL3s3p 6 nl and, predominantly, KL3s 2 3p 4 nln'l' of neutral argon are seen, together with some lines from the argon ion. Assignments of observed lines are discussed using the MO model, the Wigner spin conservation rule, and previous experimental data for these systems.