Fig. 1. (a) Schematic diagram of the experimental setup for a single shock target on the SG-II laser, with a similar configuration used for counter-propagating shocks. (b), (c) Cross-sections of single and counter-propagating shock targets.

Fig. 2. (a)–(c) View of the piston: (a) X-ray emission from the laser–piston interaction from a time-integrated pinhole camera diagnostic; (b) microscope image of the 1 mm diameter shock aperture and CH–Br/CH pistons; (c) lineout of (a) and Gaussian fit to estimate the laser spot size. (d), (e) Target view: field of view of the X-ray backlighting diagnostic of a single shock target and example of raw X-ray image result, respectively.

Fig. 3. XRBL results for (a) single and (b) colliding shocks. Artefacts from hard X-ray background (see Figure 2(e)) have been removed for visual purposes. For colliding shocks, the position is taken relative to the left-hand side piston and the vertical arrows mark the approximate position of the shock fronts in each frame. The arrows suggest that the shocks interpenetrate; however, in reality the experiments are in a collisional regime where no interpenetration occurs.

Fig. 4. Shock front position as a function of time measured from the results in Figure 3 for single and colliding shocks. For the latter, the positions of the shock fronts are marked in Figure 3(b) with matching colours.

Fig. 5. Numerical simulations of the experiments with the 2D radiation hydrodynamics code ARWEN at 20 ns. (a) Maps of mass density and temperature. (b) Axial lineouts (at a radius of 0 mm) of mass density, temperature, materials and ionization from (a).