Uri Shumlak

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A discontinuous Galerkin method for the full two-fluid plasma model is described. The plasma model includes complete electron and ion fluids, which allows charge separation, separate electron and ion temperatures and velocities. Complete Maxwell's equations are used including displacement current. The algorithm is validated by benchmarking against existing(More)
A discontinuous Galerkin method for the ideal 5 moment two-fluid plasma system is presented. The method uses a second or third order discontinuous Galerkin spatial discretization and a third order TVD Runge-Kutta time stepping scheme. The method is benchmarked against an analytic solution of a dispersive electron acoustic square pulse as well as the(More)
Algorithms for the solution of the five-moment ideal Two-Fluid equations are presented. The ideal Two-Fluid model is more general than the often used magnetohydrodynamic (MHD) model. The model takes into account electron inertia effects, charge separation and the full electromagnetic field equations and allows for separate electron and ion motion. The(More)
The multi-fluid plasma model only assumes local thermodynamic equilibrium within each fluid, e.g. ion and electron fluids for the two-fluid plasma model. Derivation of the MHD model involves several asymptotic and simplifying assumptions that can limit its applicability. Therefore, the two-fluid plasma model more accurately represents the appropriate(More)
Theoretical studies have predicted that the Z-pinch can be stabilized with a sufficiently sheared axial flow [U. Shumlak and C. W. Hartman, Phys. Rev. Lett. 75, 3285 (1995)]. A Z-pinch experiment is designed to generate a plasma which contains a large axial flow. Magnetic fluctuations and velocity profiles in the plasma pinch are measured. Experimental(More)
a r t i c l e i n f o a b s t r a c t This paper describes a study of the effects of the overall spatial resolution, polynomial degree and computational grid directionality on the accuracy of numerical solutions of a highly anisotropic thermal diffusion equation using the spectral element spatial discretization method. The high-order spectral element(More)
The Zeeman effect has been used for measurement of magnetic fields in low-temperature plasma, but the diagnostic technique is difficult to implement in a high-temperature plasma. This paper describes new instrumentation and methodology for simultaneous measurement of the entire Doppler-broadened left and right circularly polarized Zeeman spectra in(More)