Fusion ignition

Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the reaction heats the fuel mass more rapidly than it cools. In other words, fusion ignition is the point at which the increasing self-heating of the nuclear fusion removes the need for external heating.[1] This is quantified by the Lawson criterion.[2] Ignition can also be defined by the fusion energy gain factor.[3]

In the laboratory, fusion ignition defined by the Lawson criterion was first achieved in August 2021,[4] and ignition defined by the energy gain factor was achieved in December 2022,[5][6] both by the U.S. National Ignition Facility.

  1. ^ Chandler, David L. (10 May 2010). "New project aims for fusion ignition". MIT News. MIT. Retrieved 24 February 2012.
  2. ^ Lawson, J. D. (December 1955). "Some Criteria for a Power Producing Thermonuclear Reactor". Proceedings of the Physical Society, Section B. 70 (1): 6–10. Bibcode:1957PPSB...70....6L. doi:10.1088/0370-1301/70/1/303.
  3. ^ Bishop, Breanna (6 February 2023). "Ignition gives U.S. 'unique opportunity' to lead world's IFE research". Lawrence Livermore National Laboratory. Retrieved 26 July 2023. This feat established a scientific energy gain of 1.5, over the gain of 1 used by the National Academy of Sciences to define ignition
  4. ^ Abu-Shawareb, H.; Acree, R.; Adams, P. (8 August 2022). "Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment". Phys. Rev. Lett. 129 (7): 075001. doi:10.1103/PhysRevLett.129.075001. hdl:10044/1/99300. PMID 36018710.
  5. ^ Clery, Daniel (13 December 2022). "With historic explosion, a long sought fusion breakthrough". Science. doi:10.1126/science.adg2803. Retrieved 13 December 2022.
  6. ^ David Kramer (13 December 2022), "National Ignition Facility surpasses long-awaited fusion milestone", Physics Today, 2022 (2), American Institute of Physics: 1213a, doi:10.1063/PT.6.2.20221213a, S2CID 254663644, The shot at Lawrence Livermore National Laboratory on 5 December is the first-ever controlled fusion reaction to produce an energy gain.