RICHTMYER-MESHKOV INSTABILITY WITH STRONG RADIATIVELY DRIVEN SHOCKS

The Richtmyer-Meshkov instability is investigated with strong radiativ ely driven shocks (Mach>20, 5Xcompression) using the Nova laser. The t arget consists of a solid density ablator and lower-density plastics ( Atwood number A<0) in planar geometry to facilitate in-flight radiogra phic diagnosis. Perturbations eta=eta(0) cos kx are imposed at the int erface to seed the instability. The experiments agree with full hydrod ynamic simulations over a wide variety of conditions. For small initia l amplitudes \A\k eta(0)<1, the growth rate agrees with a linear impul sive model using the average of the pre- and post-shock initial amplit udes. For \A\k eta(0)>1, the growth rate is limited to the difference between the transmitted shock speed and the interface speed. (C) 1996 American Institute of Physics.