Anomalous X-Ray Emission at Early Stages of Hot-Spot Formation in Deuterium-Tritium Cryogenic Implosions

We recently reported data from deuterium–tritium cryogenic implosions that show an onset of hot-spot x-ray self-emission at a larger shell radius than is predicted by a 1-D radiation-hydrodynamic implosion model.[1] A candidate explanation is the presence of unmodeled sources of hydrodynamic perturbations, leading to an increase of hot-spot mass at the start of deceleration. Alternatively, mistimed shock formation may relax the dense shell profile, leading to the accelerated development of the hot spot. We will review the previous results and discuss new experiments designed to arbitrate these candidate hypotheses by characterizing the emission onset for implosions with stability increased by use of a thicker initial cryogenic layer (i.e., reduced in-flight aspect ratio).

[1] R. C. Shah et al., Phys. Rev. E 103, 023201 (2021).