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Title: Modification of the formation of high-Mach number electrostatic shock-like structures by the ion acoustic instability

The formation of unmagnetized electrostatic shock-like structures with a high Mach number is examined with one- and two-dimensional particle-in-cell (PIC) simulations. The structures are generated through the collision of two identical plasma clouds, which consist of equally hot electrons and ions with a mass ratio of 250. The Mach number of the collision speed with respect to the initial ion acoustic speed of the plasma is set to 4.6. This high Mach number delays the formation of such structures by tens of inverse ion plasma frequencies. A pair of stable shock-like structures is observed after this time in the 1D simulation, which gradually evolves into electrostatic shocks. The ion acoustic instability, which can develop in the 2D simulation but not in the 1D one, competes with the nonlinear process that gives rise to these structures. The oblique ion acoustic waves fragment their electric field. The transition layer, across which the bulk of the ions change their speed, widens and their speed change is reduced. Double layer-shock hybrid structures develop.
Authors:
 [1] ; ; ;  [2] ;  [3] ;  [4]
  1. Department of Science and Technology, Linköping University, SE-60174 Norrköping (Sweden)
  2. Centre for Plasma Physics, School of Mathematics and Physics, Queen's University of Belfast, Belfast BT7 1NN (United Kingdom)
  3. Univ Potsdam, Inst Phys and Astron, D-14476 Potsdam (Germany)
  4. (Germany)
Publication Date:
OSTI Identifier:
22218504
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOUNDARY LAYERS; ELECTRIC FIELDS; ELECTRONS; ION ACOUSTIC WAVES; IONS; LANGMUIR FREQUENCY; MACH NUMBER; NONLINEAR PROBLEMS; PLASMA INSTABILITY; PLASMA SIMULATION; SHOCK WAVES; SUPERSONIC FLOW; TWO-DIMENSIONAL CALCULATIONS