Shock-Augmented Ignition Approach to Laser Inertial Fusion

TY - JOUR

T1 - Shock-Augmented Ignition Approach to Laser Inertial Fusion

AU - Barlow, D.

AU - Trickey, W.

AU - Ruocco, A.

AU - Glize, K.

AU - Antonelli, L.

AU - Khan, M.

AU - Woolsey, N. C.

N1 - © 2022 American Physical Society. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details Funding Information: This work was funded by EPSRC Grants No. EP/P023460/1 and No. EP/P026796/1. R. H. H. S. would like to thank D. Callahan, O. Hurricane, A. Kritcher, O. Landen, K. Newman, R. Nora, H. Robey, V. Smalyuk, C. Weber, A. Zylstra, and others at Lawrence Livermore National Laboratory for their various ongoing contributions.

PY - 2022/11/4

Y1 - 2022/11/4

N2 - Shock ignition enables high gain at low implosion velocity, reducing ablative Rayleigh-Taylor instability growth, which can degrade conventional direct drive. With this method, driving a strong shock requires high laser power and intensity, resulting in inefficiencies in the drive and the generation of hot electrons that can preheat the fuel. A new "shock-augmented ignition"pulse shape is described that, by preconditioning the ablation plasma before launching a strong shock, enables the shock ignition of thermonuclear fuel, but importantly, with substantially reduced laser power and intensity requirements. The reduced intensity requirement with respect to shock ignition limits laser-plasma instabilities, such as stimulated Raman and Brillouin scatter, reducing the risk of hot-electron preheat and restoring the laser coupling advantages of conventional direct drive. Simulations indicate that, due to the reduced power requirements, high gain (∼100) ignition of large-scale direct drive implosions (outer radius ∼1750 μm, deuterium-tritium ice thickness ∼165 μm) may be possible within the power and energy limits of existing facilities such as the National Ignition Facility. Moreover, this concept extends to indirect drive implosions, which exhibit substantial yield increases at reduced implosion velocity. Shock-augmented ignition expands the viable design space of laser inertial fusion.

AB - Shock ignition enables high gain at low implosion velocity, reducing ablative Rayleigh-Taylor instability growth, which can degrade conventional direct drive. With this method, driving a strong shock requires high laser power and intensity, resulting in inefficiencies in the drive and the generation of hot electrons that can preheat the fuel. A new "shock-augmented ignition"pulse shape is described that, by preconditioning the ablation plasma before launching a strong shock, enables the shock ignition of thermonuclear fuel, but importantly, with substantially reduced laser power and intensity requirements. The reduced intensity requirement with respect to shock ignition limits laser-plasma instabilities, such as stimulated Raman and Brillouin scatter, reducing the risk of hot-electron preheat and restoring the laser coupling advantages of conventional direct drive. Simulations indicate that, due to the reduced power requirements, high gain (∼100) ignition of large-scale direct drive implosions (outer radius ∼1750 μm, deuterium-tritium ice thickness ∼165 μm) may be possible within the power and energy limits of existing facilities such as the National Ignition Facility. Moreover, this concept extends to indirect drive implosions, which exhibit substantial yield increases at reduced implosion velocity. Shock-augmented ignition expands the viable design space of laser inertial fusion.

UR - http://www.scopus.com/inward/record.url?scp=85141561130&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.129.195001

DO - 10.1103/PhysRevLett.129.195001

M3 - Article

AN - SCOPUS:85141561130

SN - 0031-9007

VL - 129

JO - Physical Review Letters

JF - Physical Review Letters

IS - 19

M1 - 195001

ER -