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Magnetic Reconnection During Flux Conversion in a Driven Spheromak

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.2040207· OSTI ID:881061
During buildup of a spheromak by helicity injection, magnetic reconnection converts toroidal flux into poloidal flux. This physics is explored in the resistive magnetohydrodynamic code, NIMROD [C.R. Sovinec, A.H. Glasser, T.A. Gianakon, D.C. Barnes, R.A. Nebel, S.E. Kruger, D.D. Schnack, S.J. Plimpton, A. Tarditi, and M.S. Chu, J. Comp. Phys., 195, 355-386 (2004)], which reveals negative current sheets with {lambda} = {mu}{sub 0}j {center_dot} B/B{sup 2}reversed relative to the applied current. The simulated event duration is consistent with magnetic diffusion on the sheet thickness and is accompanied by cathode voltage spikes and poloidal field increases similar to those seen in the Sustained Spheromak Physics Experiment, SSPX [E. B. Hooper, L. D. Pearlstein, and R. H. Bulmer, Nucl. Fusion 39, 863 (1999)]. All magnetic fieldlines are open during reconnection and their trajectories are very sensitive to their starting points, resulting in chaos. The current sheets are most intense inside the separatrix near the X-point of the mean-field spheromak, suggesting that the reconnection occurs near fieldlines which are closed in the azimuthal average.
Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
881061
Report Number(s):
UCRL-JRNL-212785
Journal Information:
Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
Country of Publication:
United States
Language:
English

References (30)

Experimental Test of the Sweet-Parker Model of Magnetic Reconnection journal April 1998
The impedance and energy efficiency of a coaxial magnetized plasma source used for spheromak formation and sustainment journal August 1990
A theoretical foundation of general magnetic reconnection journal January 1988
Measurement of the Current Sheet during Magnetic Reconnection in a Toroidal Plasma journal January 2003
Energetic particles from three-dimensional magnetic reconnection events in the Swarthmore Spheromak Experiment journal May 2002
Formation and sustainment of electrostatically driven spheromaks in the resistive magnetohydrodynamic model journal February 2001
Three-dimensional kinematic reconnection of plasmoids journal January 1991
Simulation of spheromak evolution and energy confinement journal May 2005
Relaxation and magnetic reconnection in plasmas journal July 1986
Nonlinear magnetohydrodynamics simulation using high-order finite elements journal March 2004
Three-Dimensional Magnetic Reconnection in Astrophysical Plasmas - MHD Approach journal January 1998
Experimental Identification of the Kink Instability as a Poloidal Flux Amplification Mechanism for Coaxial Gun Spheromak Formation journal May 2003
Numerical Investigation of Transients in the SSPX Spheromak journal January 2005
Studies of Plasma Expelled from a Coaxial Plasma Gun journal January 1964
MHD equilibria in a spheromak sustained by coaxial helicity injection journal July 1999
Experimental study of the relaxation cycle of a decaying spheromak in an external magnetic field journal June 1991
Review of spheromak research journal June 1994
Instantaneous current and field structure of a gun-driven spheromak for two gun polarities journal November 2002
Controlled and spontaneous magnetic field generation in a gun-driven spheromak journal May 2005
Chaotic Scattering and Self-Organization in Spheromak Sustainment journal November 2000
Suppression of MHD Fluctuations Leading to Improved Confinement in a Gun-Driven Spheromak journal March 2002
Initial results from investigation of three‐dimensional magnetic reconnection in a laboratory plasma journal August 1991
Ion Acceleration and Direct Ion Heating in Three-Component Magnetic Reconnection journal April 1996
NIMROD: A computational laboratory for studying nonlinear fusion magnetohydrodynamics journal May 2003
Experimental investigation of three‐dimensional magnetic reconnection by use of two colliding spheromaks journal October 1993
Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment journal May 2001
Magnetic reconnection and the topology of interacting twisted flux tubes journal November 1996
Plasma current drive by helicity injection in relaxed states journal February 1989
General magnetic reconnection, parallel electric fields, and helicity journal January 1988
Relaxation Phonomena in the High-Temperature S-1 Spheromak journal December 1988

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