The structure of bow shocks formed by the interaction of pulsed-power driven magnetised plasma flows with conducting obstacles
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
We present an experimental study of the development and structure of bow shocks produced by the interaction of a magnetised, collisional, super-Alfvénic plasma flow with conducting cylindrical obstacles. The plasma flow with an embedded, frozen-in magnetic field (ReM ∼ 20) is produced by the current-driven ablation of fine aluminium wires in an inverse, exploding wire array z-pinch. We show that the orientation of the embedded field with respect to the obstacles has a dramatic effect on the bow shock structure. When the field is aligned with the obstacle, a sharp bow shock is formed with a global structure that is determined simply by the fast magneto-sonic Mach number. When the field is orthogonal to the obstacle, magnetic draping occurs. This leads to the growth of a magnetic precursor and the subsequent development of a magnetised bow shock that is mediated by two-fluid effects, with an opening angle and a stand-off distance, that are both many times larger than in the parallel geometry. By changing the field orientation, we change the fluid regime and physical mechanisms that are responsible for the development of the bow shocks. MHD simulations show good agreement with the structure of well-developed bow shocks. However, collisionless, two-fluid effects will need to be included within models to accurately reproduce the development of the shock with an orthogonal B-field.
Date Issued
2017-07-14
Date Acceptance
2017-06-25
Citation
PHYSICS OF PLASMAS, 2017, 24 (7)
ISSN
1070-664X
Publisher
AIP Publishing
Journal / Book Title
PHYSICS OF PLASMAS
Volume
24
Issue
7
Copyright Statement
© 2017 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas 24, 072713 (2017); doi: 10.1063/1.4993187 and may be found at https://dx.doi.org/10.1063/1.4993187
Sponsor
AWE Plc
U.S Department of Energy
Engineering & Physical Science Research Council (EPSRC)
U.S Department of Energy
Royal Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000406767900055&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
30236912/0
675350-9958
EP/N013379/1
416729-G
Subjects
Science & Technology
Physical Sciences
Physics, Fluids & Plasmas
Physics
Z-PINCHES
FIELDS
SIMULATIONS
0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics
0201 Astronomical And Space Sciences
0203 Classical Physics
Fluids & Plasmas
Publication Status
Published
Article Number
ARTN 072713