Thickness of an embedded ion shock

The thickness of an ion shock embedded in a collisional shock propagating in an electron proton gas is calculated, using both the kinetic theory and the continuum approach, for the free stream Mach numbers M=3 to M→∞. It is found that the shock thickness predicted by the kinetic theory is 2–4 times the thickness obtained from the continuum approach. It is also found that the electric field, via which the electrons are compressed across the ion shock, although representing considerable dissipation of the ion kinetic energy, has very little effect on the ion shock broadening.