Feature

Novel Methods for Diagnosing Mixing and Laser-Fusion Target Performance Using X-ray Spectroscopy of an Embedded Titanium Layer

Barukh Yaakobi, Frederic J. Marshall, David K. Bradley, Jacques A. Delettrez, Robert S. Craxton, and Reuben Epstein, Laboratory for Laser Energetics, Univ. of Rochester, Rochester, N.Y.

In current direct-drive laser fusion experiments, shell targets containing thermonuclear fuel (D-T) are uniformly irradiated by a powerful multi-beam laser, leading to compression and heating. Imperfect irradiation uniformity results in hydrodynamically unstable implosions, which lead to mixing of target layers and reduction in heating and compression. Recent experiments on the 60-beam OMEGA laser system at the Laboratory for Laser Energetics show that the inclusion of a thin titanium layer within the shell yields novel and significant diagnostic signatures of target behavior.