THE NATIONAL IGNITION FACILITY: STATUS AND PROGRESS TOWARDS FUSION IGNITION

摘要

The National Ignition Facility (NIF), the world's largest and most energetic laser system, built for studying inertial confinement fusion (ICF) and high-energy-density (HED) science, is operational at Lawrence Livermore National Laboratory (LLNL). A primary goal of the early experimental campaign on NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn with gain. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC) effort to achieve fusion ignition. NIC is a multi-institution partnership between LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the University of Rochester Laboratory for Energetics (LLE). NIC also includes a variety of collaborators from universities, national laboratories as well as international collaborators. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition in the laboratory and developing a predictable fusion experimental platform. The results from experiments completed so far are encouraging and show promise for the achievement of ignition. Capsule implosion experiments at energies up to 1.3 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and will focus the world's attention on the possibility of IFE as a carbon-free, practically limitless energy option. This paper describes the unprecedented experimental capabilities of NIF and the results achieved so far on the path toward ignition, for stockpile stewardship, and the beginning of frontier science experiments. The paper will also address plans to transition NIF to a national user facility, providing access for researchers in the international high energy density science field.