Possibilities of obtaining laser action from singly ionised iron group elements through charge transfer in hollow cathode lasers

A survey is given of the general energy level structure of the singly ionised iron group elements. Recent analyses have yielded a large number of new levels that can be populated through charge transfer collisions with noble-gas ions at thermal energies. Line enhancement caused by this reaction has been observed in many cases in hollow cathode discharges (HCD), and it might therefore be possible to construct HCD lasers with iron group elements as the active medium.