Nuclear scientists using lasers the size of three football pitches said they had generated a huge amount of energy from fusion, possibly offering hope for the development of a new clean energy source.

Scientists at the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California said the experiment suggests the goal of “ignition”, where the energy released by fusion exceeds that delivered by the laser, is now within touching distance.

NIF said the experiment, on 8 August, made a significant step toward ignition, achieving a yield of more than 1.3 megajoules. This advancement puts researchers at the threshold of fusion ignition, an important goal of the NIF, and opens access to a new experimental regime.