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Observation of collisionless shocks in a large current‐free laboratory plasma
Author(s) -
Niemann C.,
Gekelman W.,
Constantin C. G.,
Everson E. T.,
Schaeffer D. B.,
Bondarenko A. S.,
Clark S. E.,
Winske D.,
Vincena S.,
Van Compernolle B.,
Pribyl P.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl061820
Subject(s) - plasma , physics , ion , shock wave , shock (circulatory) , coupling (piping) , magnetohydrodynamics , magnetic field , dissipation , piston (optics) , atomic physics , current (fluid) , laser , mechanics , materials science , optics , nuclear physics , thermodynamics , medicine , quantum mechanics , wavefront , metallurgy
We report the first measurements of the formation and structure of a magnetized collisionless shock by a laser‐driven magnetic piston in a current‐free laboratory plasma. This new class of experiments combines a high‐energy laser system and a large magnetized plasma to transfer energy from a laser plasma plume to the ambient ions through collisionless coupling, until a self‐sustained M A ∼ 2 magnetosonic shock separates from the piston. The ambient plasma is highly magnetized, current free, and large enough (17 m × 0.6 m) to support Alfvén waves. Magnetic field measurements of the structure and evolution of the shock are consistent with two‐dimensional hybrid simulations, which show Larmor coupling between the debris and ambient ions and the presence of reflected ions, which provide the dissipation. The measured shock formation time confirms predictions from computational work.