Effects of the Density of Gaseous Targets on Electron Capture and Loss by Fast Heavy Ions

Recent experimental charge-exchange studies of heavy ions have been utilized to modify the theory of Bohr and Lindhard for electron capture and loss by heavy ions passing through dense gases. New results are presented for the difference between the average ion charges obtained in dense and dilute gases, as well as for the residual ion excitation after charge-changing collisions. Implications are indicated for the measurement of radiative lifetimes of excited heavy ions.