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Title: Interpenetration and deflection phenomena in collisions between supersonic, magnetized, tungsten plasma flows diagnosed using high resolution optical Thomson scattering

An optical Thomson scattering diagnostic has been used to investigate collisions between supersonic, magnetized plasma flows, in particular the transition from collisionless to collisional interaction dynamics. These flows were produced using tungsten wire array z-pinches, driven by the 1.4 MA 240 ns Magpie generator at Imperial College London. Measurements of the collective-mode Thomson scattering ion-feature clearly indicate that the ablation flows are interpenetrating at 100 ns (after current start), and this interpenetration continues until at least 140 ns. The Thomson spectrum at 150 ns shows a clear change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams near the axis. The Thomson scattering data also provide indirect evidence of the presence of a significant toroidal magnetic field embedded in the “precursor” plasma near the axis of the array over the period 100–140 ns; these observations are in agreement with previous measurements [Swadling et al., Phys. Rev. Lett. 113, 035003 (2014)]. The Thomson scattering measurements at 150 ns suggest that this magnetic field must collapse at around the time the dense precursor column begins to form.
Authors:
; ; ; ; ; ; ; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)
  2. Sandia National Laboratories, PO Box 5800, Albuquerque, New Mexico 87185-1193 (United States)
  3. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)
  4. Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAE, Mianyang 621900 (China)
Publication Date:
OSTI Identifier:
22490014
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 7; Other Information: (c) 2015 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; ABLATION; COLLISIONS; INTERACTIONS; IONS; MAGNETIC FIELDS; PLASMA; PLASMA DIAGNOSTICS; SPECTRA; THOMSON SCATTERING; TUNGSTEN; WIRES