83 / 2025-03-13 08:52:37

Interface slit-induced implosion asymmetry in double-shell targets: Time-resolved high-energy X-ray radiography with 10-µm spatial resolution

interface slit, double shell targets, radiography

In inertial confinement fusion (ICF) research, multiple ignition schemes exist. Among them, the double-shell target emerges as a particularly appealing approach, boasting a series of significant advantages. These include the utilization of noncryogenic deuterium–tritium (DT) fuel, more reliable shock timing control, a reduced ignition temperature threshold, and a relatively lower convergence requirement. During the fabrication process of a double-shell target, the outer shell is typically composed of two hemispherical shells. Inevitably, a joint gap is formed at the junction of these hemispherical shells, and this gap is likely to exert a substantial influence on the implosion performance of the target. To comprehensively investigate the impact of the joint feature, we propose a novel approach involving X-ray radiography. This method employs micro-sized high-energy X-rays generated by a picosecond laser. The X-ray backlighter, with a size of approximately 10 microns and a duration of tens of picoseconds, enables the achievement of exceptionally high temporal and spatial resolution. Through this experimental setup, we have successfully obtained radiographic images of the inner shell of the double-shell target at various time points. These images distinctly illustrate the influence of the joint feature of the outer shell on the target's structure and dynamics. Based on the acquired radiographic images, a detailed analysis of the areal density distribution of the target is conducted. Using the experimental parameters, radiation hydrodynamics simulations are also performed. Intriguingly, a structure closely resembling the experimental results is observed in the simulations, further validating the significance and reliability of our experimental findings.