Curtis, Alden, authorCalvi, Chase, authorTinsley, James, authorHollinger, Reed, authorKaymak, Vural, authorPukhov, Alexander, authorWang, Shoujun, authorRockwood, Alex, authorWang, Yong, authorShlyaptsev, Vyacheslav N., authorRocca, Jorge J., authorNature Research, publisher2020-04-282020-04-282018-03-14Curtis, A., Calvi, C., Tinsley, J. et al. Micro-scale fusion in dense relativistic nanowire array plasmas. Nat Commun 9, 1077 (2018). https://doi.org/10.1038/s41467-018-03445-zhttps://hdl.handle.net/10217/206008Nuclear fusion is regularly created in spherical plasma compressions driven by multi-kilojoule pulses from the world’s largest lasers. Here we demonstrate a dense fusion environment created by irradiating arrays of deuterated nanostructures with joule-level pulses from a compact ultrafast laser. The irradiation of ordered deuterated polyethylene nanowires arrays with femtosecond pulses of relativistic intensity creates ultra-high energy density plasmas in which deuterons (D) are accelerated up to MeV energies, efficiently driving D–D fusion reactions and ultrafast neutron bursts. We measure up to 2 × 106 fusion neutrons per joule, an increase of about 500 times with respect to flat solid targets, a record yield for joule-level lasers. Moreover, in accordance with simulation predictions, we observe a rapid increase in neutron yield with laser pulse energy. The results will impact nuclear science and high energy density research and can lead to bright ultrafast quasi-monoenergetic neutron point sources for imaging and materials studies.born digitalarticlesenglaser-matter interactionshigh energy density plasmasneutron productionplasma productionneutron sourcesplasma diagnosticsplasma acceleratorsTextThis article is open access and distributed under the terms and conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0).https://doi.org/10.1038/s41467-018-03445-z