Enhanced collisionless shock formation in a magnetized plasma containing a density gradient.
Two-dimensional hybrid simulations of super-Alfvénic expanding debris plasma interacting with an inhomogeneous ambient plasma are presented. The simulations demonstrate improved collisionless coupling of energy to the ambient ions when encountering a density gradient. Simulations of an expanding cylinder running into a step function gradient are performed and compared to a simple analytical theory. Magnetic flux probe data from a laboratory shock experiment are compared to a simulation with a more realistic debris expansion and ambient ion density. The simulation confirms that a shock is formed and propagates within the high density region of ambient plasma.
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Clark
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Everson
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Schaeffer
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Bondarenko
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Constantin
Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA.
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Niemann
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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Winske