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Related papers: Local and global Fokker-Planck neoclassical calcul…

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We interpret a class of nonlinear Fokker-Planck equations with reaction as gradient flows over the space of Radon measures equipped with the recently introduced Hellinger-Kantorovich distance. The driving entropy of the gradient flow is not…

Functional Analysis · Mathematics 2019-08-13 Stanislav Kondratyev , Dmitry Vorotnikov

An approximate analytical solution to the fluctuation potential problem in the modified Poisson-Boltzmann theory of electrolyte solutions in the restricted primitive model is presented. The solution is valid for all inter-ionic distances,…

Statistical Mechanics · Physics 2017-12-15 E. O. Ulloa-Dávila , L. B. Bhuiyan

This paper describes new modeling capabilities for predicting H-mode pedestal profiles in spherical tokamaks. Temperature profiles for NSTX discharges 132543 and 132588 are modeled by coupling the \textsc{astra} transport solver with…

The particle transport of impurities in magnetically confined plasmas under some conditions does not find, neither quantitatively nor qualitatively, a satisfactory theory-based explanation. This compromise the successful realization of…

Stronger impurity density in-out poloidal asymmetries than predicted by the most comprehensive neoclassical models have been measured in several tokamaks around the world during the last decade, calling into question the reduction of…

Plasma Physics · Physics 2020-06-23 Silvia Espinosa , Peter J. Catto

Kinetics of metastable systems modeled by Hamiltonians containing nonlocal and nonconservative terms is reproduced by the Fokker-Planck and imaginary time Schrodinger equation scheme with subsequent symplectic integration. Example solutions…

Materials Science · Physics 2007-05-23 E. Klotins

The primitive model describes ions by point charges with an additional hard-core interaction. In classical density-functional theory the mean-field electrostatic contribution can be obtained from the first order of a functional perturbation…

Soft Condensed Matter · Physics 2022-04-06 Moritz Bültmann , Andreas Härtel

Under low-collisionality conditions the isotropic part of the electron velocity distribution function in a plasma becomes non-local and the electrons can be described by a single global distribution function . This is also the regime…

Plasma Physics · Physics 2019-09-24 Uwe Czarnetzki

This study presents the investigation of the connection between radial electric field, gradient of Reynolds stress and Long Range Correlation (LRC), as a proxy for Zonal Flows (ZF), in different plasma scenarios in the TJ-II stellarator.…

Plasma Physics · Physics 2020-01-08 R. Gerrú , S. Mulas , U. Losada , F. Castejón , B. Liu , T. Estrada , B Ph van Milligen , C. Hidalgo

A theory of non-local linear ion-temperature-gradient (ITG) drift modes while retaining non-adiabatic electrons is presented, extending the previous work [S. Moradi, et al {\em Phys. Plasmas} {\bf 18}, 062106 (2011)]. A dispersion relation…

Plasma Physics · Physics 2012-08-14 Sara Moradi , Johan Anderson , B. Weyssow

We propose a general method to identify nonlinear Fokker--Planck--Kolmogorov equations (FPK equations) as gradient flows on the space of probability measures on $\mathbb{R}^d$ with a natural differential geometry. Our notion of gradient…

Analysis of PDEs · Mathematics 2024-11-11 Marco Rehmeier , Michael Röckner

We consider a Fokker-Planck equation which is coupled to an externally given time-dependent constraint on its first moment. This constraint introduces a Lagrange-multiplier which renders the equation nonlocal and nonlinear. In this paper we…

Analysis of PDEs · Mathematics 2018-11-28 Simon Eberle , Barbara Niethammer , André Schlichting

Due to the smallness of the volumes associated with the flux surfaces around the O-point of a magnetic island, the electron cyclotron power density applied inside the island for the stabilization of neoclassical tearing modes (NTMs) can…

Plasma Physics · Physics 2014-04-04 B. Ayten , E. Westerhof , ASDEX Upgrade Team

A new type of instability - electrokinetic instability - and an unusual transition to chaotic motion near a charge-selective surface was studied by numerical integration of the Nernst-Planck-Poisson-Stokes system and a weakly nonlinear…

Fluid Dynamics · Physics 2014-02-17 E. A. Demekhin , N. V. Nikitin , V. S. Shelistov

In the Nernst-Planck equations in two or more dimensions, a non-Faradaic electric current can arise as a consequence of connecting patches with different liquid junction potentials. Whereas this current vanishes for binary electrolytes or…

Soft Condensed Matter · Physics 2020-07-01 Patrick B Warren

Classical theory of the electric double layer is based on the fundamental assumption of a dilute solution of point ions. There are a number of situations such as high applied voltages, high concentration of electrolytes, systems with…

Fluid Dynamics · Physics 2015-06-11 Brian D. Storey , Martin Z. Bazant

We develop a Luttinger liquid theory of the Coulomb drag of persistent currents flowing in concentric mesoscopic rings, by incorporating non-linear corrections to the electron dispersion relation. We demonstrate that at low temperatures,…

Mesoscale and Nanoscale Physics · Physics 2009-10-28 T. V. Shahbazyan , S. E. Ulloa

Self-oscillation is a phenomenon studied across many scientific disciplines, including the engineering of efficient heat engines and electric generators. We investigate the single electron shuttle, a model nano-scale system that exhibits a…

Statistical Mechanics · Physics 2019-07-03 C. W. Wächtler , P. Strasberg , S. H. L. Klapp , G. Schaller , C. Jarzynski

Hydrodynamic electron flow is experimentally observed in the differential resistance of electrostatically defined wires in the two-dimensional electron gas in (Al,Ga)As heterostructures. In these experiments current heating is used to…

Condensed Matter · Physics 2009-10-22 M. J. M. de Jong , L. W. Molenkamp

We study temperature dependence of the critical current modulation Ic(H) for two types of planar Josephson junctions: a low-Tc Nb/CuNi/Nb and a high-Tc YBa2Cu3O7 bicrystal grain-boundary junction. At low T both junctions exhibit a…

Superconductivity · Physics 2015-06-15 A. A. Boris , A. Rydh , T. Golod , H. Motzkau , A. M. Klushin , V. M. Krasnov