Contributions of the National Ignition Facility to the development of inertial fusion energy

The US Department of Energy is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory early in the next century. The NIF will use a > 1.8 MJ, 0.35 urn laser with 192 independent beams, a SO-fold increase over the energy of the Nova laser. System performance analyses suggest yields as great as 20 MJ may be achievable. NIF will conduct more than 600 shots per year. The benefits of a micro-fusion capability in the laboratory include essential contributions to defence programs, resolution of important Inertial Fusion Energy (IFE) issues and unparalleled conditions of energy density for basic science and technology research. A start has been made to consider the role the NIF will fill in the development of IFE. While the achievement of ignition and gain speaks for itself in terms of its impact on developing IFE, it is believed there are areas of IFE development, such as fusion power technology, IFE target design and fabrication and understanding chamber dynamics, that would significantly benefit from NIF experiments. In the area of IFE target physics, ion targets will be designed using the NIF laser and the feasibility of high-gain targets will be confirmed. Target chamber dynamics experiments will benefit from X-ray and debris energies that mimic the spatial distribution of neutron heating, activation and tritium breeding in relevant materials. IFE target systems will benefit from evaluating low-cost target fabrication techniques by testing such targets on NIF. Additionally, it is believed that it is feasible to inject up to four targets and engage them with the NIF laser by triggering the beams in groups of ca. 50 separated in time by ca. 0.1 s. Sub-ignition neutron yields would allow an indication of symmetry achieved in such proof-of-principle rep-rate experiments. NIF will be a unique source of data to benchmark predictive capabilities to support affordable IFE technology selections. The total of NIF-IFE experiments may involve several thousands of shots. NIF may support design “certification” for the follow-on facility to NIF, dedicated to IFE, called the Engineering Test Facility. 0920-3796/95/$09.50 ,f; 1995 Elsevier Science S.A. All rights reserved SSDI 0920-3796( 94)00365-3 4 M. Tohin et ul. / Fusion Engineering and Design 29 (1995) 3-17