TIME EVOLUTION OF KELVIN–HELMHOLTZ VORTICES ASSOCIATED WITH COLLISIONLESS SHOCKS IN LASER-PRODUCED PLASMAS

Journal Article · Sat Sep 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/828/2/93· OSTI ID:22667449

Kuramitsu, Y.; Moritaka, T. ^[1]; Mizuta, A. ^[2]; Sakawa, Y.; Tanji, H.; Ide, T.; Sano, T. ^[3]; Koenig, M.; Ravasio, A.; Pelka, A. ^[4]; Takabe, H. ^[5]; Gregory, C. D. ^[6]; Woolsey, N. ^[7]; Matsukiyo, S. ^[8]; Matsumoto, Y. ^[9]

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1. Department of Physics, National Central University, No. 300, Jhongda Rd., Jhongli, Taoyuan, 320, Taiwan (China)
2. Computational Astrophysics Laboratory, RIKEN, Wako 351-0198 (Japan)
3. Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka, 565-0871 (Japan)
4. Laboratoire pour l’Utilisation des Lasers Intenses, UMR 7605, CNRS—CEA—Université Paris VI—Ecole Polytechnique, F-91128 Palaiseau Cedex (France)
5. Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, D-01328 Dresden (Germany)
6. Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom)
7. York Plasma Institute, Department of Physics, University of York, York, YO10 5DD (United Kingdom)
8. Department of Earth System Science and Technology, Kyushu University, 6-1 Kasuga-Koen, Kasuga, 816-8580, Fukuoka (Japan)
9. Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)

We report experimental results on Kelvin–Helmholtz (KH) instability and resultant vortices in laser-produced plasmas. By irradiating a double plane target with a laser beam, asymmetric counterstreaming plasmas are created. The interaction of the plasmas with different velocities and densities results in the formation of asymmetric shocks, where the shear flow exists along the contact surface and the KH instability is excited. We observe the spatial and temporal evolution of plasmas and shocks with time-resolved diagnostics over several shots. Our results clearly show the evolution of transverse fluctuations, wavelike structures, and circular features, which are interpreted as the KH instability and resultant vortices. The relevant numerical simulations demonstrate the time evolution of KH vortices and show qualitative agreement with experimental results. Shocks, and thus the contact surfaces, are ubiquitous in the universe; our experimental results show general consequences where two plasmas interact.

• OSTI ID: 22667449
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 828; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASYMMETRY
COMPUTERIZED SIMULATION
DENSITY
EVOLUTION
FLUCTUATIONS
HYDRODYNAMIC MODEL
INSTABILITY
INTERACTIONS
LASER-PRODUCED PLASMA
SHOCK WAVES
SURFACES
TIME RESOLUTION
TURBULENCE
UNIVERSE
VELOCITY