m

F Nous contacter

0

Documents  76X05 | enregistrements trouvés : 17

O
     

-A +A

P Q

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Proceedings of symposia in applied mathematics , 0005

Localisation : Collection 1er étage

76-06 ; 76Exx ; 76X05

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Partial Differential Equations;Mathematical Physics

Gyrokinetic simulation is considered to be an essential tool to study turbulent transport driven by micro-scale instabilities in tokamak plasmas. It is roughly categorized into two approaches; delta-$f$ local and full-$f$ global approaches. In full-$f$ approach, both turbulent transport and profile evolutions are solved self-consistently under the power balance between external heat source/sink. In this talk, we address (A) numerical technique to treat such full-$f$ gyrokinetic Vlasov-Poisson equations [1] and (B) characteristics of global ion-scale turbulence and transport barrier [2]. We also discuss (C) the role of stable modes in collisionless or weakly collisional plasmas [3]. Gyrokinetic simulation is considered to be an essential tool to study turbulent transport driven by micro-scale instabilities in tokamak plasmas. It is roughly categorized into two approaches; delta-$f$ local and full-$f$ global approaches. In full-$f$ approach, both turbulent transport and profile evolutions are solved self-consistently under the power balance between external heat source/sink. In this talk, we address (A) numerical technique ...

76X05 ; 65Mxx ; 76F10 ; 82D10

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Partial Differential Equations;Mathematical Physics

We investigate the gyrokinetic limit for the two-dimensional Vlasov-Poisson system in a regime studied by F. Golse and L. Saint-Raymond [1, 3]. First we establish the convergence towards the Euler equation under several assumptions on the energy and on the norms of the initial data. Then we analyze the asymptotics for a Vlasov-Poisson system describing the interaction of a bounded density of particles with a moving point charge, characterized by a Dirac mass in the phase-space. We investigate the gyrokinetic limit for the two-dimensional Vlasov-Poisson system in a regime studied by F. Golse and L. Saint-Raymond [1, 3]. First we establish the convergence towards the Euler equation under several assumptions on the energy and on the norms of the initial data. Then we analyze the asymptotics for a Vlasov-Poisson system describing the interaction of a bounded density of particles with a moving point charge, characterized by ...

76X05 ; 82C21 ; 35Q35 ; 35Q83 ; 35Q60 ; 82D10

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Mathematical Physics

This series of 4 lectures discusses the key physical processes in fusion-relevant plasmas, the equations used to describe them, and the interrelationships between them. The focus is on developing comprehensive equations and models for magnetically-confined fusion plasmas on a hierarchy of time scales. The relevant plasma equations for inertial fusion are also briefly mentioned. The pedagogical development begins with the very short time scale microscopic charged-particle-based Coulomb collision processes in a plasma. This microscopic description is then used to develop a comprehensive plasma kinetic equation, fluid moment, magnetohydrodynamic (MHD) and hybrid kinetic/fluid moment plasma descriptions, and finally the long time scale equations for plasma transport across the confining magnetic field. The present grand challenge in magnetic fusion is to develop a "predictive capability" for deuteron-triton (D-T) burning plasmas in ITER (http://www.iter.org). Individual .pdf files of the final, corrected sets of viewgraphs are available via http://homepages.cae.wisc.edu/~callen/plasmas.

This initial lecture first discusses the wide range of characteristic length and time scales involved in modeling fusion plasmas. Next, the Coulomb scattering of a charged test particle's velocity and the differences between the ensemble-averaged electron and ion collisional scattering and relaxation rates are discussed. Then, the mathematical properties of these collisional scattering processes are used to develop a Fokker-Planck collision operator. Finally, a general plasma kinetic equation (PKE) is developed and its general properties discussed.
This series of 4 lectures discusses the key physical processes in fusion-relevant plasmas, the equations used to describe them, and the interrelationships between them. The focus is on developing comprehensive equations and models for magnetically-confined fusion plasmas on a hierarchy of time scales. The relevant plasma equations for inertial fusion are also briefly mentioned. The pedagogical development begins with the very short time scale ...

76X05 ; 82C70

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Mathematical Physics

In this second lecture a Green function solution of the perturbed plasma kinetic equation (PKE) that determines the effects of Coulomb collisional scattering on linear Landau damping is presented first. This is followed by the development of the fluid moment equations obtained from the PKE. An extended Chapman-Enskog-type approach is used to determine the needed collisional and fluid moment closures for this comprehensive, hybrid kinetic/fluid model. Finally, closures for collision-dominated unmagnetized and magnetized plasmas are presented and their limitations discussed. In this second lecture a Green function solution of the perturbed plasma kinetic equation (PKE) that determines the effects of Coulomb collisional scattering on linear Landau damping is presented first. This is followed by the development of the fluid moment equations obtained from the PKE. An extended Chapman-Enskog-type approach is used to determine the needed collisional and fluid moment closures for this comprehensive, hybrid kinetic/fluid ...

76X05 ; 82C70

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Mathematical Physics

The subject matter of this talk concerns the derivation of the Finite Larmor radius approximation, when collisions are taken into account.
Several studies are performed, corresponding to different collision kernels. The main motivation consists in computing the gyro-average of the Fokker-Planck- Landau operator, which plays a major role in plasma physics. We determine its equilibria and derive the fluid approximation around them, leading to a new Euler type system of conservation laws.
The main technique applies for studying highly anisotropic parabolic problems, for example the heat equation with disparate diffusion coeffcients with respect to the parallel and perpendicular directions.
The subject matter of this talk concerns the derivation of the Finite Larmor radius approximation, when collisions are taken into account.
Several studies are performed, corresponding to different collision kernels. The main motivation consists in computing the gyro-average of the Fokker-Planck- Landau operator, which plays a major role in plasma physics. We determine its equilibria and derive the fluid approximation around them, leading to a ...

82D10 ; 76X05

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Partial Differential Equations;Mathematical Physics

KEEN - Vlasov plasmas - acoustic waves - semi-Lagrangian scheme - Vlasov-Poisson equation; - BGK mode

76X05 ; 82D10 ; 65M60

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 103 p.
ISBN 978-0-7073-0324-6

Localisation : Ouvrage RdC (MAXW)

champ électromagnétique # électromagnétisme # force électronique # relativité

76X05 ; 83C50

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Localisation : Réserve

arc électrique # conductibilité électrique de gaz # corps électrique en mouvement # décharge dans les lampes à vide # décharge par étincelle # décharge à travers des gaz sous forte pression # détermination de la conduction portée par un ion négatif # détermination de la relation de la conduction à la masse d'u # effet photoélectrique # effet suscité par un champ magnétique sur le mouvement des i # ionisation dans les gaz enflammés # ionisation par la lumière # ionisation par un corps qui brûle # passage d'électricité dans le gaz # propriété d'un gaz en état de conduction # rayons cathodiques # rayons de Röntgen, Becquerel # théorie mathématique de la conduction d'électricité à traver arc électrique # conductibilité électrique de gaz # corps électrique en mouvement # décharge dans les lampes à vide # décharge par étincelle # décharge à travers des gaz sous forte pression # détermination de la conduction portée par un ion négatif # détermination de la relation de la conduction à la masse d'u # effet photoélectrique # effet suscité par un champ magnétique sur le mouvement des i # ionisation dans les gaz enflammés # ionisation ...

76X05 ; 78-03 ; 81Vxx

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 222 p.
ISBN 978-2-84299-055-8

Series in applied mathematics , 0002

Localisation : Ouvrage RdC (DECO)

EDP # collision # flux de gaz ionisé dans un champs électromagnétique # hydrodynamique quantique # hydrodynamique relativiste # modélisation # mécanique des fluides # plasma # superfluide # théorie cinétique des gaz # équation de transport # équation mathématique de la physique

35Q99 ; 76P05 ; 76X05 ; 76Y04 ; 82C40 ; 82D10 ; 82D50

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 516 p.

Localisation : Fonds Russe réserve

équation de Vlasov # théorie de l'oscillation du plasma # propriété de Laplace # interval de Cauchy

76W05 ; 76X05

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 241 p.
ISBN 978-0-89871-367-1

Localisation : Ouvrage RdC (GLASS)

problème de Cauchy # théorie cinétique des gaz # équation de la physique # équation de Boltzmann # flot plasmique # plasma # mécanique statistique # système de Vlasov-Poisson # Système de Vlasov-Maxwell

82C40 ; 35Qxx ; 76P05 ; 76X05 ; 82-02 ; 82D10

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Panoramas et synthèses , 0039;0040

Localisation : Collection 1er étage

amortissement Landau # dynamique galactique # écho plasma # eulérien # fréquence cyclotron # fusion # limite faible nombre de Mach # longueur de Debye # magnétohydrodynamique # modèles fluides de plasmas # méthode de Newton # méthodes computationnelles # nombre de Mach # particle-in-cell # physique des plasmas # plasma de fusion magnétique # quasi-neutralité # régime de dérive-fluide # schémas conservatifs # schémas de capture de chocs # schémas implicites # schémas `Asymptotic-Preserving' # semi-lagrangien # simulations de calcul haute performance # théorie gyrocinétique # théorie KAM # tokamak # transport turbulent # Vlasov-Poisson. amortissement Landau # dynamique galactique # écho plasma # eulérien # fréquence cyclotron # fusion # limite faible nombre de Mach # longueur de Debye # magnétohydrodynamique # modèles fluides de plasmas # méthode de Newton # méthodes computationnelles # nombre de Mach # particle-in-cell # physique des plasmas # plasma de fusion magnétique # quasi-neutralité # régime de dérive-fluide # schémas conservatifs # schémas de capture de chocs # schémas ...

76L05 ; 76N10 ; 76N20 ; 76W05 ; 76X05 ; 82C99 ; 82D10 ; 85A05

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Mathematical Physics

In this third lecture the ideal and extended magnetohydrodynamics (MHD) fluid moment descriptions of magnetized plasmas are discussed first. The ideal MHD equilibrium in a toroidally axisymmetric tokamak plasma is discussed next. Then, the collisional viscous force closure moments and their effects on the parallel Ohm's law and poloidal flows in the extended MHD model of tokamak plasmas are discussed. Finally, the species fluid moment equations are transformed to magnetic flux coordinates, averaged over a flux surface and used to obtain the tokamak plasma transport equations. These equations describe the transport of the plasma electron density, plasma toroidal angular momentum and pressure of the electron and ion species "radially" across the nested tokamak toroidal magnetic flux surfaces. In this third lecture the ideal and extended magnetohydrodynamics (MHD) fluid moment descriptions of magnetized plasmas are discussed first. The ideal MHD equilibrium in a toroidally axisymmetric tokamak plasma is discussed next. Then, the collisional viscous force closure moments and their effects on the parallel Ohm's law and poloidal flows in the extended MHD model of tokamak plasmas are discussed. Finally, the species fluid moment equations ...

76X05 ; 82C70

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

Research talks;Mathematical Physics

In this final, fourth lecture the many effects on radial tokamak plasma transport caused by various physical processes are noted first: transients, collision- and microturbulence-induced transport, sources and sinks, and small three-dimensional (3-D) magnetic field perturbations. The main focus of this lecture is on the various effects of small 3-D fields on plasma transport which is a subject that has come of age over the past decade. Finally, the major themes of these CEMRACS 2014 lectures are summarized and a general framework for combining extended MHD, hybrid kinetic/fluid and transport models of tokamak plasma behavior into unified descriptions and numerical simulations that may be able to provide a "predictive capability" for ITER plasmas is presented. In this final, fourth lecture the many effects on radial tokamak plasma transport caused by various physical processes are noted first: transients, collision- and microturbulence-induced transport, sources and sinks, and small three-dimensional (3-D) magnetic field perturbations. The main focus of this lecture is on the various effects of small 3-D fields on plasma transport which is a subject that has come of age over the past decade. Finally, ...

76X05 ; 82C70

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 138 p.

Localisation : Ouvrage RdC (BOUR)

Tokamak # contrôle optimal # fusion nucléaire # optimisation lagrangien # physique des plasma

76X05 ; 81V35

... Lire [+]

Déposez votre fichier ici pour le déplacer vers cet enregistrement.

- 85 p.

Localisation : Ouvrage RdC (CROU)

simulation numérique # équation de Vlasov # plasma

76M25 ; 76X05 ; 76-02 ; 78M10

... Lire [+]

Z