Improved wavelengths of n=2-2 transitions in ionised titanium

Abstract
The allowed n=2-2 transitions in titanium ions with three- to nine-electron systems are prominent features in the extreme ultraviolet spectrum of the DITE Tokamak operated with titanium gettering. The appearance of the lines in high order and their proximity to other well documented impurity lines which are used as transfer standards of wavelength has allowed precision wavelength measurements of the Delta n=2-2 transitions. Accurate values of the energy intervals in the configurations 1s22s22pk (k=1-5) are of topical interest for the predictions of forbidden (M1) transitions within the ground configurations.