Prepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
نویسنده
چکیده
Simulations of electron transport are carried out by solving the Fokker-Planck equation in the diffusive approximation. The system of a single laser hot spot, with open boundary conditions, is systematically studied by performing a scan over a wide range of the two relevant parameters: (1) Ratio of the stopping length over the width of the hot spot. (2) Relative importance of the heating through inverse Bremsstrahlung compared to the thermalization through self-collisions. As for uniform illumination [J. P. Matte et al., Plasma Phys. Controlled Fusion 30, 1665 (1988)], the bulk of the velocity distribution functions (VDFs) present a super-Gaussian dependence. However, as a result of spatial transport, the tails are observed to be well represented by a Maxwellian. A similar dependence of the distributions is also found for multiple hot spot systems. For its relevance with respect to stimulated Raman scattering, the linear Landau damping of the electron plasma wave is estimated for such VDFs. Finally, the non-linear Fokker-Planck simulations of the single laser hot spot system are also compared to the results obtained with the linear non-local hydrodynamic approach [A. V. Brantov et al., Phys. Plasmas 5, 2742 (1998)], thus providing a quantitative limit to the latter method: The hydrodynamic approach presents more than 10% inaccuracy in the presence of temperature variations of the order ∆T/T ∼ 1%, and similar ∗E-mail: [email protected]
منابع مشابه
Prepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
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Prepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
متن کامل
Prepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
متن کامل
Prepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
A diagnostic to measure the loss of energetic ions from the Wendelstein 7-AS (W7-AS) stellarator has been built. It is capable of measuring losses of both neutral beam ions and energetic ions arising from ion cyclotron resonant heating. The probe can measure losses of both clockwise and counterclockwise-going energetic ions simultaneously , and accepts a wide range of pitch angles in both direc...
متن کاملPrepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
Equilibrium considerations infer that large localized radial electric fields are associated with internal transport barrier structures in tokamaks and other toroidal magnetic confinement configurations. In this paper, the effects of an equilibrium electric field on fast magnetosonic wave propagation are considered in the context of a cold plasma model.
متن کاملPrepared for the U.s. Department of Energy, under Contract De-ac02-76ch03073 Princeton Plasma Physics Laboratory Princeton University, Princeton, New Jersey
A computational study of resistive drift waves in the edge plasma of a stellarator with an helical magnetic axis is presented. Three coupled field equations, describing the collisional drift wave dynamics in the linear approximation, are solved as an initial-value problem along the magnetic field line. The magnetohydrodynamic equilibrium is obtained from a three-dimensional local equilibrium mo...
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