Results 1 - 10 of 4154
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[en] Ultracold neutral plasmas provide a new and valuable system in which to study fundamental plasma physics and the effects of strong coupling. In this paper, we provide a brief overview of the field of ultracold neutral plasmas. Then we describe new results from the use of fluorescence from a sheet of laser light as a probe of ion equilibration and expansion dynamics in these systems. This new probe opens many possibilities for studying thermal transport and equilibration in a strongly coupled plasma.
[en] The degenerate state of cold matter (at density 10 Mg - 10 Tg/cu cm and magnetic fields 2-50 TG) which is stable with regard to beta(-) processes and pycnonuclear reactions is characterized theoretically using a noninteracting-particle model. The thermodynamic and nuclear parameters for relatively and absolutely stable thermodynamic-equilibrium states are given in tables and graphs, and the applicability of the model is demonstrated. These electron-nuclear and electron-neutron-nuclear phases are qualitatively similar to those found in the exteriors of pulsars
[en] The propagation of ordinary bulk modes coupled with extraordinary surface modes in coaxial metal waveguides completely filled with cold magnetoactive plasma is investigated theoretically. The interaction between modes propagating across the waveguide axis in the presence of the axial and azimuthal components of the external magnetic field is examined. The effect of the azimuthal magnetic field on the dispersion properties of these modes is thoroughly studied for the case of a uniform plasma.
[en] Complete text of publication follows. Field line resonances (FLRs) observed in the magnetosphere often have the amplitude of a few nT, which indicates that dB/B roughly satisfies ∼0.01. It is well known that the FLRs are excited by compressional waves via mode conversion, but there has been no apparent criterion on the maximum amplitude in the regime of linear approximations. Such limited range of amplitude should be understood by including nonlinear saturation of FLRs, which has not been examined until now. In this study, using a three-dimensional magnetohydrodynamic (MHD) simulation code, we examine the evolution of nonlinear field line resonances (FLRs) in the cold plasmas. The MHD code used in this study allows a full nonlinear description and enables us to study the maximum amplitude of FLRs. When the disturbance is sufficiently small, it is shown that linear properties of MHD wave coupling are well reproduced. In order to examine a nonlinear excitation of FLRs, it is shown how these FLRs become saturated as the initial magnitude of disturbances is assumed to increase. Our results suggest that the maximum amplitude of FLRs become saturated at the level of the same order of dB/B as in observations. In addition, we discuss the role of both linear terms and nonlinear terms in the MHD wave equations.