Charge-exchange collisions are one of the effective pumping
methods for soft X-ray lasers. Experiments are performed
to investigate charge-exchange collisions between highly
charged Mg ions in colliding laser-produced magnesium plasmas.
Pinhole photography and XUV spectroscopy are used as diagnostic
tools. Spectroscopic studies show selective population
of n = 3 levels of Mg IX ions, which results in
enhancement of respective line intensities. Theoretical
calculations also give a large cross section as high as
10−15 cm2 for these charge-exchange
collisions when the relative velocities of the colliding ions
are of the order of 107 cm s−1.
XUV pinhole pictures are taken in early stages, which give
more insight into the expansion dynamics of the colliding
magnesium plasmas.