NIF achieves target gain greater than unity for the first time
At the National Ignition Facility, 2.05 MJ of 351 nm ultraviolet laser light delivered to an indirect-drive target produced a total fusion yield reported in Physical Review Letters as approximately 3.1 MJ, and in the laboratory's public announcement as 3.15 MJ, giving a target gain of about 1.5 and significantly exceeding the Lawson criterion for ignition. This is scientific breakeven with respect to the laser energy delivered to the target, and it is the first time any laboratory achieved it. It is not wall-plug breakeven: firing that shot required on the order of 300 to 400 MJ drawn from the electrical grid, with about 330 MJ stored in the capacitor banks, an overall efficiency well below one percent. No electricity was generated. The Physical Review Letters paper reporting the result carried more than 1,370 authors from 44 institutions.
Observed — measured or witnessed, with the observation cited.
Subjects
- National Ignition Facility · research facility · United States
- Inertial confinement fusion · confinement concept · not located
- Fusion energy gain (Q) and target gain · physical quantity · not located
- Breakeven · physical threshold · not located
- Lawson criterion · physical criterion · not located
- Tritium · isotope · not located
- Deuterium · isotope · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent. This is the standing of the weakest source, not an average.
Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment
On 5 December 2022 a NIF indirect-drive implosion achieved a target gain of 1.5, with 2.05 MJ of 351 nm laser light producing about 3.1 MJ of fusion yield and significantly exceeding the Lawson criterion for ignition
Physical Review Letters (American Physical Society) · 2024-02-05 · Verified
H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 132, 065102 (2024), DOI 10.1103/PhysRevLett.132.065102
Energy Principles of Scientific Breakeven in an Inertial Fusion Experiment
Sets out the physics design changes — reduced coast time and maximised hot-spot internal energy — behind the first laser indirect-drive experiment to exceed target gain of unity, and frames the result explicitly as scientific breakeven
Physical Review Letters (American Physical Society) · 2024-02-05 · Verified
A. L. Kritcher et al., Phys. Rev. Lett. 132, 065103 (2024), DOI 10.1103/PhysRevLett.132.065103
LLNL's breakthrough ignition experiment highlighted in Physical Review Letters / Achieving Fusion Ignition
The laboratory's own statement of the December 2022 energy figures, of the repeat target-gain shots in 2023, and of the 1,370-author PRL paper
Lawrence Livermore National Laboratory, National Ignition Facility & Photon Science · 2024-02 · Partly verified
LLNL news release and NIF programme page, lasers.llnl.gov/science/achieving-fusion-ignition and llnl.gov/article/50801; states 2.05 MJ in, 3.15 MJ out on 5 December 2022, and the 30 July 2023 shot at 2.05 MJ in, 3.88 MJ out
The commercial drive for laser fusion power
The energy actually drawn from the grid to fire a NIF ignition shot exceeds the fusion yield by roughly two orders of magnitude, so target gain above unity is not wall-plug breakeven
Physics Today (AIP Publishing) · 2023 · Partly verified
Physics Today online feature, pubs.aip.org/physicstoday/online/31501; states that NIF stored about 330 MJ of electrical energy in capacitor banks to deliver roughly 2.2 MJ of ultraviolet photons to target, giving a wall-plug efficiency of order 0.5–1%
Recorded on National Ignition Facility
- JET's DTE1 campaign sets the first deuterium-tritium fusion power record
- JET's DTE2 campaign releases 59 MJ in a single pulse
- NIF exceeds the Lawson criterion for ignition
- NIF achieves target gain greater than unity for the first time
- JET ceases plasma operations after 105,842 pulses
- NIF repeats target gain and raises the yield to 3.88 MJ
- JET sets the single-pulse fusion energy record of 69.26 MJ
- NIF achieves ignition for the sixth time
- NIF reaches 8.6 MJ yield and a target gain of 4.13
- Commonwealth Fusion Systems' declared target for net energy gain at SPARC
- ITER's declared target date for the start of deuterium-tritium operation
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- NIF reaches 8.6 MJ yield and a target gain of 4.13 · 2025-04-07
- NIF achieves ignition for the sixth time · 2024-11-18
- Commonwealth Fusion Systems' declared target for net energy gain at SPARC · 2027
- ITER's declared target date for the start of deuterium-tritium operation · 2039
- JET sets the single-pulse fusion energy record of 69.26 MJ · 2023-10-03
- NIF repeats target gain and raises the yield to 3.88 MJ · 2023-07-30
- JET ceases plasma operations after 105,842 pulses · 2023-12
- NIF exceeds the Lawson criterion for ignition · 2021-08-08