Inertial Confinement Fusion (ICF or IF) is the scheme by which some hope to harness the fusion reaction for energy production. While offering the potential of relatively clean, plentiful energy, without greenhouse gas emissions, the approach must succeed in orchestrating a large number of complicated physical processes, meeting severe engineering challenges, and satisfying stringent economic requirements. Fusion is known to work if the reactor is large enough, e.g., the sun or a hydrogen bomb. However, achieving the necessary conditions at smaller scale poses enormous difficulty. Laboratory research begun in the 1970's is approaching its next serious hurdle.

The National Ignition Facility (NIF) is a large laser built to test the feasibility of igniting a small amount of heavy hydrogen fuel in the laboratory, a major step in testing the scientific feasibility of ICF. The project, sited at Lawrence Livermore National Laboratory and pursued under the auspices of the US NNSA, has performed a successful "integrated experiment", with all major laser, diagnostic, and target systems operating properly. If ignition is achieved (energy output about equal to the energy required to compress the fuel), prospects for using ICF to produce energy become significantly greater.

See https://publicaffairs.llnl.gov/news/news_releases/2010/nnsa/NR-NNSA-10-10-02.html for more details. Photo from the NNSA press release.