(Color) Dynamic hohlraum schematic diagram. Voltage applied across the top and bottom electrodes causes current to flow through the wire arrays. The magnetic pressure accelerates the wire plasma onto the foam, forming a hohlraum.
A typical capsule cross section is shown in (a). The radial dimensions are in microns. The fill pressure is nominally Ar. The plot in (b) is a measurement of wall thickness variations characteristic of the best CH∕PVA capsules used in these experiments.
Side-view and end-view radiographs of the target assembly used in the Z1467 experiment.
Time-resolved x-ray images obtained in experiment Z882. The capsule was a -inner-diameter, -thick CH∕PVA shell filled with Ar. Each plot is a horizontal lineout through the corresponding frame. The lineout intensities are in arbitrary units, scaled to optimize the visibility of the features in each snapshot.
The foam shock velocity (a) inferred from x-ray images similar to Fig. 4, acquired in 13 separate Z experiments. The solid line is the most probable value obtained by computing a weighted mean for the data. The dashed lines are the uncertainties in the weighted mean. The trajectory plot in (b) is the ensemble of the 60 measurements obtained in the 13 experiments displayed in (a). The line is the trajectory corresponding to a fit to the ensemble, defined such that corresponds to the shock arrival at the axis. The collection of data from each experiment was time shifted to minimize the difference with the mean velocity trajectory.
(Color) Comparison of postprocessed simulations with the trajectory measurements obtained in experiments with -inner-diameter,-thick CH wall capsules. The red dots are the measured shock velocity, time shifted to the weighted mean velocity trajectory (red dash). The green dots are the measured capsule trajectory. The blue, red, and green lines are postprocessed simulation results for the radiation temperature at the capsule, the foam shock trajectory, and the capsule trajectory, respectively.
Neutron time-of-flight measurements (a) from detectors at different distances confirm that the neutron energy is consistent with DD thermonuclear neutron production. The ratio of the measured and 2D unperturbed simulated yield for the best performing CH wall implosions is 20–30% (b).
Time- and space-resolved Ar emission spectra from experiment Z1467. Both spectrometers viewed the capsule from the side, through the tungsten Z-pinch plasma. TREX5 acquired data with spatial resolution parallel to the equator and TREX6 acquired data with spatial resolution parallel to the polar axis. The times are with respect to the foam shock arrival at the axis. The uncertainty in the absolute timing is at , since shock measurements were not obtained in the Z1467 experiment.
Comparison of postprocessed simulations with the spectra obtained in experiment Z1467.
Time-resolved spatially averaged implosion core temperature and density inferred from the Z1467 TREX5 data and from the synthetic spectra obtained by postprocessing LASNEX simulations of the implosion. The density curves marked with a “+” and “*” represent the H-like Ar and He-like Ar results, respectively. The experimental temperature uncertainties are approximately and the density uncertainties are .
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