Direct Observations of Particle Dynamics in Magnetized Collisionless Shock Precursors in Laser-Produced Plasmas

D. B. Schaeffer, W. Fox, R. K. Follett, G. Fiksel, C. K. Li, J. Matteucci, Amitava Bhattacharjee, K. Germaschewski

Research output: Contribution to journalArticle

Abstract

We present the first laboratory observations of time-resolved electron and ion velocity distributions in magnetized collisionless shock precursors. Thomson scattering of a probe laser beam was used to observe the interaction of a laser-driven, supersonic piston plasma expanding through an ambient plasma in an external magnetic field. From the Thomson-scattered spectra we measure time-resolved profiles of electron density, temperature, and ion flow speed, as well as spatially resolved magnetic fields from proton radiography. We observe direct evidence of the coupling between piston and ambient plasmas, including the acceleration of ambient ions driven by magnetic and pressure gradient electric fields, and deformation of the piston ion flow, key steps in the formation of magnetized collisionless shocks. Even before a shock has fully formed, we observe strong density compressions and electron heating associated with the pileup of piston ions. The results demonstrate that laboratory experiments can probe particle velocity distributions relevant to collisionless shocks, and can complement, and in some cases overcome, the limitations of similar measurements undertaken by spacecraft missions.

Original languageEnglish (US)
Article number245001
JournalPhysical review letters
Volume122
Issue number24
DOIs
StatePublished - Jun 21 2019

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laser plasmas
pistons
shock
ions
velocity distribution
Thomson scattering
probes
radiography
pressure gradients
magnetic fields
complement
spacecraft
electrons
laser beams
gradients
heating
protons
electric fields
profiles
lasers

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Schaeffer, D. B., Fox, W., Follett, R. K., Fiksel, G., Li, C. K., Matteucci, J., ... Germaschewski, K. (2019). Direct Observations of Particle Dynamics in Magnetized Collisionless Shock Precursors in Laser-Produced Plasmas. Physical review letters, 122(24), [245001]. https://doi.org/10.1103/PhysRevLett.122.245001
Schaeffer, D. B. ; Fox, W. ; Follett, R. K. ; Fiksel, G. ; Li, C. K. ; Matteucci, J. ; Bhattacharjee, Amitava ; Germaschewski, K. / Direct Observations of Particle Dynamics in Magnetized Collisionless Shock Precursors in Laser-Produced Plasmas. In: Physical review letters. 2019 ; Vol. 122, No. 24.
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Direct Observations of Particle Dynamics in Magnetized Collisionless Shock Precursors in Laser-Produced Plasmas. / Schaeffer, D. B.; Fox, W.; Follett, R. K.; Fiksel, G.; Li, C. K.; Matteucci, J.; Bhattacharjee, Amitava; Germaschewski, K.

In: Physical review letters, Vol. 122, No. 24, 245001, 21.06.2019.

Research output: Contribution to journalArticle

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AU - Fiksel, G.

AU - Li, C. K.

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AU - Bhattacharjee, Amitava

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