K&agr;satellite line emission from targets irradiated by intense light ion beams can be used to diagnose plasma temperatures and densities. The fluorescence lines are created as 2pelectrons drop down to fill 1svacancies that result from ion beam‐induced ionizations. We present results from collisional‐radiative equilibrium calculations for thin Al diagnostic layers to illustrate the dependence of theK&agr;emission spectrum on temperature, density, and layer thickness. We also discuss the effects of opacity on the spectrum and the contribution fromK&agr;transitions involving excited states.