Title: High-Mach number, laser-driven magnetized collisionless shocks

Abstract

Collisionless shocks are ubiquitous in space and astrophysical systems, and the class of supercritical shocks is of particular importance due to their role in accelerating particles to high energies. While these shocks have been traditionally studied by spacecraft and remote sensing observations, laboratory experiments can provide reproducible and multi-dimensional datasets that provide complementary understanding of the underlying microphysics. We present experiments undertaken on the OMEGA and OMEGA EP laser facilities that show the formation and evolution of high-Mach number collisionless shocks created through the interaction of a laser-driven magnetic piston and magnetized ambient plasma. Through time-resolved, 2-D imaging we observe large density and magnetic compressions that propagate at super-Alfvenic speeds and that occur over ion kinetic length scales. Electron density and temperature of the initial ambient plasma are characterized using optical Thomson scattering. Measurements of the piston laser-plasma are modeled with 2-D radiation-hydrodynamic simulations, which are used to initialize 2-D particle-in-cell simulations of the interaction between the piston and ambient plasmas. The numerical results show the formation of collisionless shocks, including the separate dynamics of the carbon and hydrogen ions that constitute the ambient plasma and their effect on the shock structure. Furthermore, the simulations also show the shock separatingmore » from the piston, which we observe in the data at late experimental times.« less

Authors:

Schaeffer, Derek B. ^[1]; Fox, W.  ^[2];

• Search DOE PAGES for author "Fox, W."
• Search DOE PAGES for ORCID "0000-0001-6289-858X"

Haberberger, D. ^[3]; Fiksel, G. ^[4]; Bhattacharjee, A. ^[5]; Barnak, D. H.  ^[3];

• Search DOE PAGES for author "Barnak, D. H."
• Search DOE PAGES for ORCID "0000-0002-4646-7517"

Hu, S. X. ^[3]; Germaschewski, K.  ^[6];

• Search DOE PAGES for author "Germaschewski, K."
• Search DOE PAGES for ORCID "0000-0002-8495-6354"

Follett, R. K. ^[3]

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+ Show Author Affiliations

1. Princeton Univ., Princeton, NJ (United States)
2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
3. Univ. of Rochester, Rochester, NY (United States)
4. Univ. of Michigan, Ann Arbor, MI (United States)
5. Princeton Univ., Princeton, NJ (United States); Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
6. Univ. of New Hampshire, Durham, NH (United States)

Publication Date:

Fri Dec 08 00:00:00 EST 2017

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Princeton Univ., NJ (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE Office of Science (SC), Fusion Energy Sciences (FES)

OSTI Identifier:

1411868

Alternate Identifier(s):

OSTI ID: 1412000

Grant/Contract Number:  

NA0002731; AC05-00OR22725; SC00016249; SC0008655

Resource Type:

Accepted Manuscript

Journal Name:

Physics of Plasmas

Additional Journal Information:

Journal Volume: 24; Journal Issue: 12; Journal ID: ISSN 1070-664X

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 79 ASTRONOMY AND ASTROPHYSICS; 97 MATHEMATICS AND COMPUTING; laboratory astrophysics; high energy density physics; collisionless shocks; magnetized plasmas; particle-in-cell codes; proton radiography