Pressure-driven, resistive magnetohydrodynamic interchange instabilities in laser-produced high-energy-density plasmas
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
- Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)
Recent experiments using proton backlighting of laser-foil interactions provide unique opportunities for studying magnetized plasma instabilities in laser-produced high-energy-density plasmas. Time-gated proton radiograph images indicate that the outer structure of a magnetic field entrained in a hemispherical plasma bubble becomes distinctly asymmetric after the laser turns off. It is shown that this asymmetry is a consequence of pressure-driven, resistive magnetohydrodynamic (MHD) interchange instabilities. In contrast to the predictions made by ideal MHD theory, the increasing plasma resistivity after laser turn-off allows for greater low-mode destabilization (m>1) from reduced stabilization by field-line bending. For laser-generated plasmas presented herein, a mode-number cutoff for stabilization of perturbations with m>{approx}[8{pi}{beta}(1+D{sub m}k{sub perpendicular}{sup 2}{gamma}{sub max}{sup -1})]{sup 1/2} is found in the linear growth regime. The growth is measured and is found to be in reasonable agreement with model predictions.
- OSTI ID:
- 21294255
- Journal Information:
- Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Vol. 80, Issue 1; Other Information: DOI: 10.1103/PhysRevE.80.016407; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1539-3755
- Country of Publication:
- United States
- Language:
- English
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