Theory of the pressure broadening and shift of spectral lines

The broadening and shift of spectral lines caused by the interaction of the emitting (or absorbing) atoms with surrounding particles in the plasma are commonly observed in laboratory and astronomical spectra. A detailed analysis of the observed line shapes can give information about the density and temperature of the plasma, and in cases where the interaction between emitter and perturber is not known, some information on its form may be deduced.