J. D. Kilkenny, General Atomics for the US ICF program.
Since achieving ignition at the National Ignition Facility (NIF) as reported at IFSA 2023 the fusion output from a laser indirect drive inertial confinement fusion (ICF) target has now exceeded the energy delivered to that target by at least a factor of four with thermonuclear output more than 8 MJ. This historic achievement is built on a better of scientific understanding gained through focused and integrated experiments, modelling, and theory in concert with engineering advances to improve the laser performance, diagnostic capabilities, and target fabrication. For example a continuously tungsten doped ablator significantly improves the yield in experiments by reducing hydrodynamic instability as predicted.
The laser direct drive approach is 1) maximizing OMEGA implosion performance using statistical modelling techniques and focused experiments to improve energy coupling and compression, and 2) developing a broadband laser driver (Dw/w ~1%) to mitigate energy-coupling losses and preheat due to laser plasma instabilities as well as laser imprint for next-generation facilities (i.e., OMEGA-Next Facility and the high-yield, laser-based Next-Generation High Energy Density Facility).
The magnetic direct drive approach has continued to make progress repeatably achieving an ignition parameter “Chi” between 0.1-0.2 in experiments, more than an order of magnitude improvement over the initial MagLIF results. Furthermore, magnetic direct drive is beginning to explore new approaches, including alternative paths for preheat and composite liners that simulations show are a promising path forward.
Finally volume burn platforms of Double Shells and Pushered Single Shell are another option to pushing the code validation to different regimes of ICF concepts of alpha-heating. Achieving scientific breakeven substantially advances the long-term goal of delivering a high fusion yield on a future facility. This has spurred driver technology development and interest in both extension of current facility capabilities and entirely new facilities over the next 5-15 years. This presentation will describe these recent highlights and plans for the US program as we moved beyond ignition towards high yield.