Investigation of Focal-Spot Zooming with OMEGA Next, Wetted-Foam Target Designs at the National Ignition Facility

Indirect-drive ignition experiments at the National Ignition Facility (NIF) are laying the groundwork for the revitalization of interest in inertial fusion energy (IFE) concepts for commercial power production. As part of an overall laser-direct-drive (LDD) IFE platform, LLE is investigating advanced broadband laser designs, target fabrication, and ignition target designs.[1] The NIF offers the capability to investigate rudimentary laser zooming within the energy envelope envisioned for OMEGA Next ignition target designs. While not supporting the requisite uniformity specifications, such experiments provide an early platform on which to build a future database for both laser zooming and the application of wetted-foam targets. Results from 2-D DRACO simulations will be presented showing the effects of zooming as a function of laser-zoom defocusing, timing, and various beam-pointing geometries on the NIF. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement Number DE-NA0003856.

[1] E. M. Campbell et al., Phil. Trans. R. Soc. A 379, 20200011 (2020).