Detailed characterization of laser-produced astrophysically-relevant jets formed via a poloidal magnetic nozzle

D. P. Higginson*, G. Revet, B. Khiar, J. Béard, M. Blecher, M. Borghesi, K. Burdonov, S. N. Chen, E. Filippov, D. Khaghani, K. Naughton, H. Pépin, S. A. Pikuz, O. Portugall, C. Riconda, R. Riquier, S. N. Ryazantsev, I. Yu. Skobelev, A. Soloviev, M. StarodubtsevT. Vinci, O. Willi, A. Ciardi, J. Fuchs

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Citations (Scopus)
151 Downloads (Pure)

Abstract

The collimation of astrophysically-relevant plasma ejecta in the form of narrow jets via a poloidal magnetic field is studied experimentally by irradiating a target situated in a 20 T axial magnetic field with a 40 J, 0.6 ns, 0.7 mm diameter, high-power laser. The dynamics of the plasma shaping by the magnetic field are studied over 70 ns and up to 20 mm from the source by diagnosing the electron density, temperature and optical self-emission. These show that the initial expansion of the plasma is highly magnetized, which leads to the formation of a cavity structure when the kinetic plasma pressure compresses the magnetic field, resulting in an oblique shock [A. Ciardi et al., Phys. Rev. Lett. 110, 025002 (2013)]. The resulting poloidal magnetic nozzle collimates the plasma into a narrow jet [B. Albertazzi et al., Science 346, 325 (2014)]. At distances far from the target, the jet is only marginally magnetized and maintains a high aspect ratio due to its high Mach-number (M∼20) and not due to external magnetic pressure. The formation of the jet is evaluated over a range of laser intensities (1012–1013 W/cm2), target materials and orientations of the magnetic field. Plasma cavity formation is observed in all cases and the viability of long-range jet formation is found to be dependent on the orientation of the magnetic field.

Original languageEnglish
Pages (from-to)48-59
Number of pages12
JournalHigh Energy Density Physics
Volume23
Early online date24 Feb 2017
DOIs
Publication statusPublished - 01 Jun 2017

    Fingerprint

Keywords

  • Astrophysical plasmas
  • Jets
  • Laser-plasma interactions
  • Magnetohydrodynamics
  • Outflows

Cite this