K. Molvig

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Neoclassical transport theory is developed in a Lagrangian formulation, in contrast to the usual Eulerian development. The Lagrangian formulation is constructed from the three actions: magnetic moment, parallel invariant, and bounce averaged poloidal flux. By averaging over the fast orbital time scales an equation in the actions alone of the Fokker-Planck(More)
Clear evidence of the transition from hydrodynamiclike to strongly kinetic shock-driven implosions is, for the first time, revealed and quantitatively assessed. Implosions with a range of initial equimolar D3He gas densities show that as the density is decreased, hydrodynamic simulations strongly diverge from and increasingly overpredict the observed(More)
A kinetic theory of triggered VLF whistler emissions is given that is capable of predicting from a small scale numerical implementation the observed emission forms, and frequency-time characteristics. The present paper focuses on the theoretical developments and the explanation of the triggering process, complete with a demonstration of the threshold(More)
ABSTRACr The effect of turbulent electron diffusion from stochastic electron orbits on the stability of low beta fluctuations is considered. A set of coupled self-adjoint equations is derived for the fluctuation potentials and A,,. For the tearing mode, it is shown that stability is obtained for sufficiently large values of the diffusion coefficient,(More)
A general formulation of transport theory, specifically treating like-particle collisions, is developed for non-symmetric geometries, using the Lagrangian picture. This theory provides a particularly simple method for calculating transport coefficients which is useful for devices such as stellarators and tandem mirrors. We prove that the explicit piece of(More)
This Letter describes the theoretical structure of the plasma diffusion layer that develops from an initially sharp gas-metal interface. The layer dynamics under isothermal and isobaric conditions is considered so that only mass diffusion (mixing) processes can occur. The layer develops a distinctive structure with asymmetric and highly nonlinear features.(More)
A general purpose 2-1/2 dimensional, multifluid, time dependent computer code has been developed. This flexible tool models the dynamic behavior of plasma/neutral gas interactions in the presence of a magnetic field. The simulation has been used to examine the formation of smoke ring structure in the plasma rocket exhaust by injection of an axial jet of(More)
A derivation and approximate solution of renormalized mode coupling equations describing the turbulent drift wave spectrum is presented. Arguments are given which indicate that a weak turbulence formulation of the spectrum equations fails for a system with negative dissipation. The inadequacy of the weak turbulence theory is circumvented by utilizing a(More)
Knudsen layer losses of tail fuel ions can significantly reduce the fusion reactivity of multi-keV DT in capsules with small fuel ρr; sizable yield reduction can result for small inertial confinement fusion (ICF) capsules. This effect is most pronounced when the distance from a burning DT gas region to a nonreacting or cold wall is comparable to the mean(More)