On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

EDITORIAL article Front. Environ. Sci., 17 August 2023Sec. Freshwater Science Volume 11 - 2023 | https://doi.org/10.3389/fenvs.2023.1270348

Received 28 February 2011DOI:https://doi.org/10.1103/PhysRevLett.106.109903© 2011 American Physical Society

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

A first set of shock propagation, laser-plasma interaction, hohlraum energetics and hydrodynamic experiments have been performed using the first 4 beams of the National Ignition Facility (NIF), in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics.

This study examined the relative contributions of bacterial and phytoplankton production to the pelagic carbon flow of Lake Okeechobee, a large and shallow subtropical lake. Due to the predominance of cyanobacteria in this lake, we hypothesized that bacterial carbon flow would be larger than phytoplankton carbon flow to grazers. Using epifluorescent and light microscopy and radiotracer techniques, we measured the carbon biomass of planktonic functional groups and carbon flow between these groups. The functional groups that we used in this study included: picophytoplankton, autotrophic nanoflagellates (ANAN), microphytoplankton, bacteria, heterotrophic nanoflagellates (HNAN), ciliates, microzooplankton (rotifers and copepod nauplii) and macrozooplankton (cladocerans, copepodites and adult copepods). Microphytoplankton dominated the carbon biomass of all plankton, whereas the calanoid copepod, Diaptomus, dominated the carbon biomass of the grazers. Phytoplankton carbon flow often was higher than bacterial carbon flow to grazers; however, bacterial carbon constituted a large percentage of the total carbon flow to grazers (33.7 +/- 22.4%). Bacterial carbon provided roughly one quarter of the carbon flow to macrozooplankton (27.1 +/- 25.4%), whereas it provided half of the carbon flow to microzooplankton (57.4 +/- 20.3%) and to protozoans (47.2 +/- 25.8%). These results suggest that microbial pathways play an important role in the energetics of subtropical lake plankton communities. Although microbial loop pathways are important in many systems, direct bacterial carbon flow to macrozooplankton also may be important in copepod- and cyanobacteria-dominated lakes.

The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3omega) with a total intensity of 2 x 10(15) W cm(-2). The targets were filled with 1 atm Of CO2 producing up to 7 mm long homogeneously heated plasmas with densities of n(e) = 6 x 10(20) cm(-3) and temperatures of T-e = 2 keV. The high energy in an NIF quad of beams of 16kJ, illuminating the target from one direction, creates unique conditions for the study of laser-plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x-rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last similar to1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 3% for the smallest length (similar to2 mm), increasing to 10-12% for similar to7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modelling of the laser-plasma interactions at ignition-size scale lengths.