Direct-drive laser fusion: status, plans and future

Abstract

Laser-direct drive (LDD), along with laser indirect (X-ray) drive (LID) and magnetic drive with pulsed power, is one of the three viable inertial confinement fusion approaches to achieving fusion ignition and gain in the laboratory. The LDD programme is primarily being executed at both the Omega Laser Facility at the Laboratory for Laser Energetics and at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LDD research at Omega includes cryogenic implosions, fundamental physics including material properties, hydrodynamics and laser–plasma interaction physics. LDD research on the NIF is focused on energy coupling and laser–plasma interactions physics at ignition-scale plasmas. Limited implosions on the NIF in the ‘polar-drive’ configuration, where the irradiation geometry is configured for LID, are also a feature of LDD research. The ability to conduct research over a large range of energy, power and scale size using both Omega and the NIF is a major positive aspect of LDD research that reduces the risk in scaling from OMEGA to megajoule-class lasers. The paper will summarize the present status of LDD research and plans for the future with the goal of ultimately achieving a burning plasma in the laboratory. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 2)’.

Experimental investigation on cross-beam energy transfer between P-polarized lasers at 45-deg incidence

“…Direct-drive inertial confinement fusion (DDICF) [1][2][3] requires uniform and symmetrical laser absorption, which may be deteriorated by laser-plasma instabilities (LPIs). Crossbeam energy transfer (CBET) [4] has been considered to be one of the main contributors to the energy loss in DDICF [5], raising the priority of its mitigation.…”

Prospects for high gain inertial fusion energy: an introduction to the second edition

“…The article by Campbell et al . builds upon the research undertaken at the University of Rochester's Laboratory for Laser Energetics (LLE) over the past 6 decades and provides an up-to-date overview of the academic programme in the USA for direct-drive inertial fusion [19]. Their article describes the current status of LLE's extensive studies into cryogenic implosions, fundamental materials properties and hydrodynamics, along with laser–plasma interactions.…”