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in creator/contributor: "Romero-Talamas, C. A."  
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The Search for Reconnection and Helicity During Formation of a Bounded Spheromak

Description: Recent results from investigations using insertable magnetic probes at the Sustained Spheromak Physics Experiment (SSPX) [E. B. Hooper et al., Nucl. Fusion 39, 863 (1999)] are presented. Experiments were carried out during pre-programmed, constant amplitude coaxial gun current pulses, where magnetic field increases stepwise with every pulse, but eventually saturates. Magnetic traces from the probe, which is electrically isolated from the plasma and spans the flux conserver radius, indicate ther… more
Date: April 30, 2007
Creator: Romero-Talamas, C. A.; McLean, H. S.; Hooper, E. B.; Wood, R. D.; LoDestro, L. L. & Moller, J. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measurements and Phenomenological Modeling of Magnetic FluxBuildup in Spheromak Plasmas

Description: Internal magnetic field measurements and high-speed imaging at the Sustained Spheromak Physics Experiment (SSPX) [E. B. Hooper, L. D. Pearlstein, R. H. Bulmer, Nucl. Fusion 39, 863 (1999)] are used to study spheromak formation and field buildup. The measurements are analyzed in the context of a phenomenological model of magnetic helicity based on the topological constraint of minimum helicity in the open flux before reconnecting and linking closed flux. Two stages are analyzed: (1) the initial … more
Date: December 14, 2007
Creator: Romero-Talamas, C. A.; Hooper, E. B.; Jayakumar, R.; McLean, H. S.; Wood, R. D. & Moller, J. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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NIMROD Resistive Magnetohydrodynamic Simulations of Spheromak Physics

Description: The physics of spheromak plasmas is addressed by time-dependent, three-dimensional, resistive magneto-hydrodynamic simulations with the NIMROD code. Included in some detail are the formation of a spheromak driven electrostatically by a coaxial plasma gun with a flux-conserver geometry and power systems that accurately model the Sustained Spheromak Physics Experiment (SSPX) (R. D. Wood, et al., Nucl. Fusion 45, 1582 (2005)). The controlled decay of the spheromak plasma over several milliseconds … more
Date: December 11, 2007
Creator: Hooper, E. B.; Cohen, B. I.; McLean, H. S.; Wood, R. D.; Romero-Talamas, C. A. & Sovinec, C. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Magnetic Reconnection in the Spheromak: Physics and Consequences

Description: Magnetic reconnection in the spheromak changes magnetic topology by conversion of injected toroidal flux into poloidal flux and by magnetic surface closure (or opening) in a slowly decaying spheromak. Results from the Sustained Spheromak Physics Experiment, SSPX, are compared with resistive MHD simulations using the NIMROD code. Voltage spikes on the SSPX gun during spheromak formation are interpreted as reconnection across a negative-current layer close to the mean-field x-point. Field lines a… more
Date: February 28, 2006
Creator: Hooper, E. B.; Cohen, B. I.; Hill, D. N.; LoDestro, L. L.; McLean, H. S.; Romero-Talamas, C. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Conversion of NIMROD simulation results for graphical analysis using VisIt

Description: Software routines developed to prepare NIMROD [C. R. Sovinec et al., J. Comp. Phys. 195, 355 (2004)] results for three-dimensional visualization from simulations of the Sustained Spheromak Physics Experiment (SSPX ) [E. B. Hooper et al., Nucl. Fusion 39, 863 (1999)] are presented here. The visualization is done by first converting the NIMROD output to a format known as legacy VTK and then loading it to VisIt, a graphical analysis tool that includes three-dimensional rendering and various mathem… more
Date: May 3, 2006
Creator: Romero-Talamas, C. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Spheromak Formation and Sustainment Studies at the Sustained Spheromak Physics Experiment Using High-Speed Imaging and Magnetic Diagnostics

Description: A high-speed imaging system with shutter speeds as fast as 2 ns and double frame capability has been used to directly image the formation and evolution of the Sustained Spheromak Physics Experiment (SSPX). Reproducible plasma features have been identified with this diagnostic and divided in three groups, according to the stage in the discharge at which they occur: (1) breakdown and ejection, (2) sustainment, and (3) decay. During the first stage, plasma descends into the flux conserver shortly … more
Date: November 9, 2005
Creator: Romero-Talamas, C. A.; Holcomb, C.; Bellan, P. M. & Hill, D. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactor Opportunities for the Spheromak

Description: Experimental results from the Sustained Spheromak Physics Experiment, SSPX, are reviewed and applied to published reactor configurations. The results include several important features, including low fluctuation levels, (apparent) good magnetic flux surfaces, and moderate beta. Additional features needed for an attractive reactor but not yet demonstrated experimentally are identified by comparison with the reactor designs, and possible alternatives to a fully steady-state device are discussed.
Date: April 18, 2003
Creator: Hooper, E. B.; Bulmer, R. H.; Fowler, T. K.; Hill, D. N.; McLean, H. S.; Romero-Talamas, C. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spheromak Buildup in SSPX using a Modular Capacitor Bank

Description: The Sustained Spheromak Physics Experiment (SSPX) [1] was designed to address both magnetic field generation and confinement. The SSPX produces 1.5-3.5msec, spheromak plasmas with a 0.33m major radius and a minor radius of {approx}0.23m. DC coaxial helicity injection is used to build and sustain the spheromak plasma within the flux conserver. Optimal operation is obtained by flattening the profile of {lambda} = {mu}{sub 0}j/B, consistent with reducing the drive for tearing and other MHD modes, … more
Date: June 13, 2006
Creator: Wood, R. D.; McLean, H. S.; Hill, D. N.; Hooper, E. B. & Romero-Talamas, C. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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