Fig. 2: Diffraction patterns and extracted density profiles.

a Time sequence of the diffraction patterns, vertically offset for clarity. The unheated target (blue) has a strong absorption feature from the tungsten wire and significant refraction fringes at the plastic-vacuum boundary at ~65 μm. After heating (2.3 ns in red, 4.0 ns in yellow, 6.0 ns in green), the diffraction pattern is more complex, with strong fringe features resulting from the radial shockwave launched by the expanding tungsten, the evolution of the interface, and the rarefaction at the plastic-vacuum boundary. Data collected at 6.0 ns was clipped by the edge of the detector, making it unsuitable for full analysis. However, by aligning the signal with the estimated shock position, we can infer that the interface remains stationary at later times. b–d Density profiles corresponding to the simulated diffraction patterns (black dashed lines) in panel (a), which are fit to the experimental data. The shock velocity, estimated to be 5.35 km/s, is responsible for additional motion blurring of the refraction fringe resulting from the shock front.