Ionisation of Ti⁺, Ti²⁺and Ar²⁺by electron impact

Cross sections for the single ionisation of Ti + , Ti 2+ and Ar 2+ by electron impact have been measured in the energy range from the thresholds to 2000, 2000 and 1250 eV respectively using the fast crossed beams technique. The cross sections for Ti 2+ and Ar 2+ are compared with previously measured cross sections and with those given by the semi-empirical formula of Burgess and Chidichimo (1983). The cross section for Ti + has not been measured previously and is compared with those given by the Lotz formula and the McGuire scaled plane-wave Born approximation.