A shock-augmented ignition approach to laser inertial fusion

A new laser inertial fusion pulse-shaping concept is described. Simulations indicate that variations in the laser power driving the implosion can launch a strong shock, enabling the shock-ignition of thermonuclear fuel [1], but with substantially reduced laser power and intensity requirements. Due to the reduced power requirements, high gain (∼100) shock-augmented ignition of large-scale implosions (outer radius∼1750μm, DT-ice thickness∼165μm) may be possible within the power and energy limits of existing facilities such as the National Ignition Facility. As the implosion velocity is reduced in comparison to conventional laser direct drive designs, susceptibility to the ablative Rayleigh-Taylor instability may be reduced. Furthermore, the reduced intensity-requirement with respect to shock-ignition reduce susceptibility to laser-plasma instabilities, such as Stimulated Raman and Brillouin Scatter, increasing laser coupling and reducing hot-electron pre-heat.

This shock-augmented ignition concept has the potential to expand the viable ignition design-space of laser inertial fusion. In this talk we discuss the application of shock augmented ignition to both direct drive and indirect drive approaches.



[1] R. Betti, C. D. Zhou, K. S. Anderson, L. J. Perkins,W. Theobald, and A. A. Solodov, Phys. Rev. Lett.98,155001 (2007).