Plasma physics

  • Article
    | Open Access

    The successful in-orbit operation of an electric space propulsion system based on iodine, rather than the more expensive and difficult-to-store xenon, is demonstrated.

    • Dmytro Rafalskyi
    • , Javier Martínez Martínez
    •  & Ane Aanesland
  • Perspective |

    This Perspective discusses how high-energy-density physics could tap the potential of AI-inspired algorithms for extracting relevant information and how data-driven automatic control routines may be used for optimizing high-repetition-rate experiments.

    • Peter W. Hatfield
    • , Jim A. Gaffney
    •  & Ben Williams
  • Article |

    A weakly ionized gas jet impinging on a water surface is shown to produce a more stable cavity than does a neutral gas jet, with implications for plasma–liquid interactions.

    • Sanghoo Park
    • , Wonho Choe
    •  & Uroš Cvelbar
  • Letter |

    Radio interferometric observations of lightning over the Netherlands reveal small needle-shaped plasma structures associated with the positive leader channels, explaining why cloud-to-ground lightning connects to the ground multiple times.

    • B. M. Hare
    • , O. Scholten
    •  & P. Zucca
  • Letter |

    A solid-state propulsion system can sustain powered flight, as demonstrated by an electroaerodynamically propelled heavier-than-air aeroplane.

    • Haofeng Xu
    • , Yiou He
    •  & Steven R. H. Barrett
  • Letter |

    Ultraluminous X-ray sources are thought to be powered by accretion onto a compact object; now the discovery of X-ray emission lines and blueshifted absorption lines in the high-resolution spectra of ultraluminous X-ray sources NGC 1313 X-1 and NGC 5408 X-1 shows that in each case the compact object is surrounded by powerful winds with an outflow velocity of about 0.2 times that of light.

    • Ciro Pinto
    • , Matthew J. Middleton
    •  & Andrew C. Fabian
  • Letter |

    Laser-plasma particle accelerators offer much higher acceleration than conventional methods, which could enable high-energy applications; here two separate accelerator stages, driven by two independent lasers, are coupled using plasma-based optics.

    • S. Steinke
    • , J. van Tilborg
    •  & W. P. Leemans
  • Letter |

    Coronal mass ejections are driven by a sudden release of magnetic energy stored in flux ropes in the Sun’s corona, but when the ambient magnetic field that runs toroidally along an unstable flux rope is strong enough to prevent the flux rope from kinking, a dynamic magnetic tension force halts the eruption.

    • Clayton E. Myers
    • , Masaaki Yamada
    •  & Edward E. DeLuca
  • Letter |

    A particle accelerator that is two orders of magnitude more efficient than conventional radio-frequency accelerators is described in which positrons (rather than electrons) at the front of a bunch transfer their energy to a substantial number of positrons at the rear of the same bunch by exciting a wakefield in the plasma.

    • S. Corde
    • , E. Adli
    •  & G. Yocky
  • Letter |

    To develop plasma wakefield acceleration into a compact and affordable replacement for conventional accelerators, beams of charged particles must be accelerated at high efficiency in a high electric field; here this is demonstrated for a bunch of charged electrons ‘surfing’ on a previously excited plasma wave.

    • M. Litos
    • , E. Adli
    •  & G. Yocky
  • Letter |

    Fusion fuel gains greater than unity — which are crucial to the generation of fusion energy — are achieved on the US National Ignition Facility using the ‘high-foot’ implosion method, which reduces instability in the implosion of the fuel.

    • O. A. Hurricane
    • , D. A. Callahan
    •  & R. Tommasini
  • Letter |

    A magnetohydrodynamic simulation of a magnetized plasma at high conductivity shows that, whereas the magnetic flux can be considered ‘frozen’ into the medium for laminar flow, in a turbulent medium the motion of the field lines can become indeterministic, leading to a breakdown in flux freezing.

    • Gregory Eyink
    • , Ethan Vishniac
    •  & Alexander Szalay
  • Letter |

    The radially outward flow of plasma from the Sun is expected to be deflected when it meets the flow of interstellar plasma through which the Solar System moves, but the spacecraft Voyager 1 unexpectedly finds that the deflected, meridional, flow is consistent with zero within the transition region.

    • Robert B. Decker
    • , Stamatios M. Krimigis
    •  & Matthew E. Hill
  • Letter |

    The close binary Algol system contains a radio-bright KIV sub-giant star in a very close and rapid orbit with a main sequence B8 star. Evidence points to the existence of an extended, complex coronal magnetosphere originating at the cooler K subgiant, but the detailed morphology of the subgiant's corona and its possible interaction with its companion are unknown. Multi-epoch radio imaging of the Algol system now reveals a large coronal loop suggestive of a persistent asymmetric magnetic field structure aligned between the two stars.

    • W. M. Peterson
    • , R. L. Mutel
    •  & W. M. Goss