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Full-Text Articles in Physics
Review Of "Liquid Crystals: Fundamentals" By S. Singh, Peter J. Collings
Review Of "Liquid Crystals: Fundamentals" By S. Singh, Peter J. Collings
Physics & Astronomy Faculty Works
No abstract provided.
Test Particle Acceleration In Three-Dimensional Magnetohydrodynamic Turbulence, P. Dmitruk, W. H. Matthaeus, N. Seenu, Michael R. Brown
Test Particle Acceleration In Three-Dimensional Magnetohydrodynamic Turbulence, P. Dmitruk, W. H. Matthaeus, N. Seenu, Michael R. Brown
Physics & Astronomy Faculty Works
We perform numerical experiments of test particle acceleration on turbulent magnetic and electric fields obtained from pseudospectral direct numerical solutions of the compressible three-dimensional MHD equations. We find consistent acceleration of the particles to many times the plasma characteristic (Alfven) speed and extended power laws in the density distribution of energies. Scaling laws of maximum and mean energy of particles with the nominal gyrofrequency and the MHD electric field are observed and a simple estimate is presented.
Spheromak Merging And Field Reversed Configuration Formation At The Swarthmore Spheromak Experiment, C. D. Cothran, Abram Lockhart Falk , '03, Matthew J. Landreman , '03, Michael R. Brown, M. J. Schaffer
Spheromak Merging And Field Reversed Configuration Formation At The Swarthmore Spheromak Experiment, C. D. Cothran, Abram Lockhart Falk , '03, Matthew J. Landreman , '03, Michael R. Brown, M. J. Schaffer
Physics & Astronomy Faculty Works
The initial results of coaxial co- and counter-helicity spheromak merging studies at the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] are reported. In its new configuration, SSX is optimized to study field reversed configuration (FRC) formation and stability by counter-helicity spheromak merging. A pair of midplane coils magnetically restricts the merging process to determine how the stability of the resulting magnetic configuration depends upon the quantity of toroidal flux remaining from the initial spheromaks. The diagnostic set at SSX, featuring the capability of measuring up to 600 magnetic field components at 800 ns time resolution, …
Rapid Multiplexed Data Acquisition: Application To Three-Dimensional Magnetic Field Measurements In A Turbulent Laboratory Plasma, Matthew Joseph Landreman , '03, C. D. Cothran, Michael R. Brown, M. Kostora, J. T. Slough
Rapid Multiplexed Data Acquisition: Application To Three-Dimensional Magnetic Field Measurements In A Turbulent Laboratory Plasma, Matthew Joseph Landreman , '03, C. D. Cothran, Michael R. Brown, M. Kostora, J. T. Slough
Physics & Astronomy Faculty Works
Multiplexing electronics have been constructed to reduce the cost of high-speed data acquisition at the Swarthmore Spheromak Experiment (SSX) and Redmond Plasma Physics Laboratory. An application of the system is described for a three-dimensional magnetic probe array designed to resolve magnetohydrodynamic time scale and ion inertial spatial scale structure of magnetic reconnection in a laboratory plasma at SSX. Multiplexing at 10 MHz compresses 600 pick-up coil signals in the magnetic probe array into 75 digitizer channels. An external master timing system maintains synchronization of the multiplexers and digitizers. The complete system, calibrated and tested with Helmholtz, line current, and magnetofluid …
Has Feminism Changed Physics?, Amy Lisa Graves
Has Feminism Changed Physics?, Amy Lisa Graves
Physics & Astronomy Faculty Works
No abstract provided.
Rapid Multiplexed Data Acquisition: Application To Three-Dimensional Magnetic Field Measurements In A Turbulent Laboratory Plasma, Michael R. Brown
Rapid Multiplexed Data Acquisition: Application To Three-Dimensional Magnetic Field Measurements In A Turbulent Laboratory Plasma, Michael R. Brown
Physics & Astronomy Faculty Works
Multiplexingelectronics have been constructed to reduce the cost of high-speed data acquisition at the Swarthmore SpheromakExperiment (SSX) and Redmond Plasma Physics Laboratory. An application of the system is described for a three-dimensional magnetic probe array designed to resolve magnetohydrodynamic time scale and ion inertial spatial scale structure of magnetic reconnection in a laboratory plasma at SSX. Multiplexing at 10 MHz compresses 600 pick-up coil signals in the magnetic probe array into 75 digitizer channels. An external master timing system maintains synchronization of the multiplexers and digitizers. The complete system, calibrated and tested with Helmholtz, line current, and magnetofluid fields, reads …
Three-Dimensional Structure Of Magnetic Reconnection In A Laboratory Plasma, C. D. Cothran, Matthew Joseph Landreman , '03, Michael R. Brown, W. H. Matthaeus
Three-Dimensional Structure Of Magnetic Reconnection In A Laboratory Plasma, C. D. Cothran, Matthew Joseph Landreman , '03, Michael R. Brown, W. H. Matthaeus
Physics & Astronomy Faculty Works
The local three-dimensional structure of magnetic reconnection has been measured for the first time in a magnetohydrodynamic (MHD) laboratory plasma at the Swarthmore Spheromak Experiment. An array of 600 magnetic probes which resolve ion inertial length and MHD time scale dynamics on a single shot basis measured the magnetic structure of partial spheromak merging events. Counter-helicity spheromaks merge rapidly, and reconnection activity clearly self-generates a local component of B which breaks the standard 2D symmetry at the ion inertial scale. Consistent with prior results, no reconnection is observed for co-helicity merging.
Order Parameter Measurements Of Dichroic Dyes Dissolved In Smectic Liquid Crystals That Tilt Without Layer Contraction, Peter J. Collings, B. R. Ratna, R. Shashidhar
Order Parameter Measurements Of Dichroic Dyes Dissolved In Smectic Liquid Crystals That Tilt Without Layer Contraction, Peter J. Collings, B. R. Ratna, R. Shashidhar
Physics & Astronomy Faculty Works
Measurements of the orientational order parameter of dissolved dichroic dyes are reported for two smectic-A liquid crystals that tilt in the presence of an in-plane electric field without any decrease in the layer spacing. The dye order parameter is determined by measuring the anisotropic absorption of linearly polarized light. Different dyes are used and measurements are also performed on a smectic liquid crystal that tilts with the expected layer contraction to check how closely the measurements reflect the order parameter of the liquid crystal. The variation of the dye order parameter with electric field is in accordance with the recently …