We have modeled the temperature and density dependence of the Li‐like satellites of the Ar He &bgr; line by performing NLTE kinetic modeling of level populations in conjunction with Stark broadening calculations. Composite line profiles are computed including resonance and satellite line transitions that have built‐in the temperature and density dependence characteristic of the level populations and Stark broadening of these transitions. These synthetic spectra can be used to analyze experimental data, providing a simultaneous diagnostic of temperature and density.