Fast Ignition with Laser-Driven Ion Beams*

We report on the encouraging progress from research on fusion fast ignition (FI) initiated by carbon ions [1,2], a technologically convenient ion species from a target-fabrication perspective with advantageous characteristics for FI [2]. Specifically, we concentrate on the progress towards a quasi-monoenergetic C-ion beam with an ion energy of $\sim $ 0.5 GeV, which is necessary to penetrate to the core of the compressed DT fuel. Although all the required ion-beam parameters have not been achieved simultaneously in the present generation of high-energy, high intensity lasers, ignition-relevant performance on key parameters has been achieved in isolation on experiments at our Trident laser facility at LANL. These encouraging results include a laser conversion efficiency into ions $\sim $ 10{\%}, control of the energy spectrum (including a quasi-monoenergetic feature at the required Fi energy), and 1 GeV maximum ion energy.