Acoustic stability of nonadiabatic high-energy-density shocks

Shock waves are very efficient at compressing fluid. Ideally, the maximum mass compression ratio is $f+1$, where f accounts for molecular degrees of freedom. Sufficiently strong shocks, those that induce very high temperatures downstream, may alter f by adding vibrational modes or promoting molecular dissociation. In addition, the nonadiabaticity of these effects, and others like ionization and/or radiation, also affect the mass compression ratio and other shock properties. These changes ultimately modify the D'yakov-Kontorovich limits associated with the acoustic stability of planar isolated shocks.