The role of magnetic field in the transition to streaming ablation in wire arrays
- Laboratory of Plasma Studies, Cornell University, 316 Rhodes Hall, Ithaca, New York 14850 (United States)
In wire array Z-pinches, the magnetic field configuration and the global field penetration of individual wires play a key role in the ablation plasma dynamics. Knowledge of the magnetic field configuration is necessary to understand the ablation plasma acceleration process near the wires. Two-dimensional resistive magnetohydrodynamics simulations show that a change in the global magnetic field configuration is critical to initiating inward flow of the ablation plasma. Analysis of these simulations show that the initially compressive JxB force around a wire in its vacuum field configuration undergoes a transition to a configuration in which the Lorentz force can accelerate plasma toward the array axis. This transition is achieved through a low magnetic Reynolds number diffusive flow in which the plasma and the magnetic field are decoupled. The plasma current follows the expanding plasma toward the array axis and, after traveling a critical distance scaling with the array radius divided by the wire number, the global magnetic field threads the wire core, thereby allowing JxB coronal acceleration into ablation streams.
- OSTI ID:
- 21371134
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 5; Other Information: DOI: 10.1063/1.3392288; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ABLATION
LONGITUDINAL PINCH
LORENTZ FORCE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETIC REYNOLDS NUMBER
MAGNETOHYDRODYNAMICS
PLASMA ACCELERATION
PLASMA SIMULATION
TWO-DIMENSIONAL CALCULATIONS
WIRES
ACCELERATION
DIMENSIONLESS NUMBERS
FLUID MECHANICS
HYDRODYNAMICS
MECHANICS
PINCH EFFECT
REYNOLDS NUMBER
SIMULATION