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Full-Text Articles in Physics
Spheromak Experiment Using Separate Guns For Formation And Sustainment, Michael R. Brown, A. Martin
Spheromak Experiment Using Separate Guns For Formation And Sustainment, Michael R. Brown, A. Martin
Physics & Astronomy Faculty Works
An experiment is described that incorporates the use of separate magnetized plasma guns for formation and sustainment of a spheromak. It is shown that energy coupling efficiency approaches unity if the gun and spheromak are of comparable size. A large gun should be able to operate at lower current and therefore lower voltage. In addition, it is expected that a gun matched to the size of the spheromak will cause less perturbation to the equilibrium. It is proposed to use a smaller gun for spheromak formation and a large, efficient gun for sustainment. The theoretical basis for the experiment is …
Observation Of Light Diffusion And Correlation Transport In Nematic Liquid Crystals, M. H. Kao, Kristen Anne Jester , '94, A. G. Yodh, Peter J. Collings
Observation Of Light Diffusion And Correlation Transport In Nematic Liquid Crystals, M. H. Kao, Kristen Anne Jester , '94, A. G. Yodh, Peter J. Collings
Physics & Astronomy Faculty Works
Light diffusion and temporal correlation transport are studied in an orientationally ordered multiply scattering medium. In particular, we experimentally demonstrate the anisotropic diffusion of light through a turbid nematic liquid crystal, and we measure the temporal correlations of these diffused speckle fields for the first time. The measurements are shown to provide useful information about this material, specifically the average rotational viscosity of the director. Computer simulations corroborate both the experimental observations and a more rigorous analytic theoretical formulation of this problem.
Critical Point For The Blue-Phase-Iii-Isotropic Phase Transition In Chiral Liquid Crystals, Z. Kutnjak, C. W. Garland, Colin G. Schatz , '97, Peter J. Collings, C. J. Booth, J. W. Goodby
Critical Point For The Blue-Phase-Iii-Isotropic Phase Transition In Chiral Liquid Crystals, Z. Kutnjak, C. W. Garland, Colin G. Schatz , '97, Peter J. Collings, C. J. Booth, J. W. Goodby
Physics & Astronomy Faculty Works
The highly chiral compound S,S-4 ''-(methylbutyl)phenyl-4'-(methylbutyl) biphenyl carboxylate (S,S-MBBPC) undergoes a continuous supercritical evolution from the isotropic (I) phase to the third blue phase (BPI III). Mixtures of S,S-MBBPC and its racemate have been studied with high-resolution calorimetry capable of quantitative latent heat determinations and with optical activity measurements. Both experiments indicate that the first-order BP III-I transition line ends at a critical point when the chiral mole fraction X(c) similar or equal to 0.45. Analysis of C-p and optical activity data for the near-critical mixture with X = 0.45 indicates mean-field behavior instead of the theoretically predicted Ising fluctuation …