Turbulent collisional ionising shock waves in argon

Using an arc-driven shock tube, the turbulent features in the ion density fluctuations of an argon plasma behind collisional ionising shock fronts are determined. Fluctuation power spectra show many discrete modes and follow S(K z ) alpha K z -n with 1.2<n<2.2 for shock wave Mach numbers between 15 and 71. The overall turbulent properties are found to be almost frozen with the post-shock flow and to have particle-like dynamical behaviour.