English
Related papers

Related papers: Simulating Gyrokinetic Microinstabilities in Stell…

200 papers

The gravitationally-driven evolution of cold dark matter dominates the formation of structure in the Universe over a wide range of length scales. While the longest scales can be treated by perturbation theory, a fully quantitative…

Astrophysics · Physics 2009-11-10 Katrin Heitmann , Paul M. Ricker , Michael S. Warren , Salman Habib

In this work, a new version of KNOSOS is presented. KNOSOS is a low-collisionality radially-local, bounce-averaged neoclassical code that is extremely fast, and at the same time, includes physical effects often neglected by more standard…

The linear algorithm of the Wiener filter and constrained realizations (CRs) of Gaussian random fields is extended here to perform non-linear CRs. The procedure consists of: (1) Using low resolution data to constrain a high resolution…

Astrophysics · Physics 2009-10-30 V. Bistolas , Y. Hoffman

We apply a continuation method to recently optimized stellarator equilibria with excellent quasi-axisymmetry (QA) to generate new equilibria with a wide range of rotational transform profiles. Using these equilibria, we investigate how the…

Plasma Physics · Physics 2024-01-18 Stefan Buller , Matt Landreman , John Kappel , Rahul Gaur

Quasisymmetry can greatly improve the confinement of energetic particles and thermal plasma in a stellarator. The magnetic field of a quasisymmetric stellarator at high plasma pressure is significantly affected by the bootstrap current, but…

Plasma Physics · Physics 2022-08-17 Matt Landreman , Stefan Buller , Michael Drevlak

In this paper, several numerical examples to illustrate limitations of Quasi Steady-State (QSS) model in long-term voltage stability analysis are presented. In those cases, the QSS model provided incorrect stability assessment. Causes of…

Systems and Control · Computer Science 2013-11-27 Xiaozhe Wang , Hsiao-Dong Chiang

We introduce and derive the Fourier-enhanced 3D electrostatic field solver of the gyrokinetic full-f PIC code PICLS. The solver makes use of a Fourier representation in one periodic direction of the domain to make the solving of the system…

Analyzing recent ALICE data on inelastic pp scattering at the LHC energies we show that charged particle distributions exhibit geometrical scaling (GS). We show also that the inelastic cross-section is scaling as well and that in this case…

High Energy Physics - Phenomenology · Physics 2015-11-04 Michal Praszalowicz , Anna Francuz

We propose the existence of an infinite-parameter family of solutions in AdS that oscillate on any number of non-commensurate frequencies. Some of these solutions appear stable when perturbed, and we suggest that they can be used to map out…

High Energy Physics - Theory · Physics 2018-07-18 Matthew Choptuik , Jorge E. Santos , Benson Way

A linear stability analysis of the hydrodynamic equations of a model for confined quasi-two-dimensional granular gases is carried out. The stability analysis is performed around the homogeneous steady state (HSS) reached eventually by the…

Statistical Mechanics · Physics 2021-06-10 Vicente Garzó , Ricardo Brito , Rodrigo Soto

This paper combines results from a local gyrokinetic code with analytical theory to reconstruct the global eigenmode structure of the linearly unstable ion-temperature-gradient (ITG) mode with adiabatic electrons. The simulations presented…

Plasma Physics · Physics 2014-08-05 P. A. Abdoul , D. Dickinson , C. M. Roach , H. R. Wilson

Turbulent transport greatly impacts the performance of stellarator magnetic confinement devices. While significant progress has been made on the numerical front, theoretical understanding of turbulence in stellarators is still lacking. In…

Plasma Physics · Physics 2025-10-28 Hongxuan Zhu , H. Chen , Z. Lin , A. Bhattacharjee

Purpose: This work introduces a new lattice geometry library, egs_lattice, into the EGSnrc Monte Carlo code, which can be used for both modeling very large (previously unfeasible) quantities of geometries and establishing recursive boundary…

Medical Physics · Physics 2020-09-09 Martin P. Martinov , Rowan M. Thomson

We study the weakly nonlinear evolution of acoustic instability of a plane- parallel polytrope with thermal dissipation in the form of Newton's law of cooling. The most unstable horizontal wavenumbers form a band around zero and this…

Astrophysics · Physics 2009-10-30 O. M. Umurhan , L. Tao , E. A. Spiegel

Molecular dynamics (MD) simulations are a central tool in science and engineering enabling the study of dynamical behavior and the link between microscopic structure and macroscopic function. Their high computational cost, however, has…

Chemical Physics · Physics 2026-01-22 Salman N. Salman , Sergey A. Shteingolts , Ron Levie , Dan Mendels

The linear algorithm of the the full non-linear large scale structure of Gaussian random fields is extended here to to perform non-linear CRs. The procedure consists of: (1) Using linear CR of low resolution data to construct a high…

Astrophysics · Physics 2016-08-30 V. Bistolas , Y. Hoffman

We investigate analytically and numerically the spatial structure of the non-equilibrium stationary states (NESS) of a point particle moving in a two dimensional periodic Lorentz gas (Sinai Billiard). The particle is subject to a constant…

Chaotic Dynamics · Physics 2015-05-30 Federico Bonetto , Nikolay Chernov , Alexey Korepanov , Joel L. Lebowitz

The linear dynamics of Alfven modes in tokamaks is investigated here by means of the global gyrokinetic particle-in-cell code NEMORB. The model equations are shown and the local shear Alfven wave dispersion relation is derived, recovering…

Plasma Physics · Physics 2016-02-17 A. Biancalani , A. Bottino , S. Briguglio , A. Koenies , Ph. Lauber , A. Mishchenko , E. Poli , B. D. Scott , F. Zonca

We consider multidimensional gravitational models with a nonlinear scalar curvature term and form fields in the action functional. In our scenario it is assumed that the higher dimensional spacetime undergoes a spontaneous compactification…

High Energy Physics - Theory · Physics 2007-05-23 U. Guenther , P. Moniz , A. Zhuk

Stochastic spectral methods have achieved great success in the uncertainty quantification of many engineering problems, including electronic and photonic integrated circuits influenced by fabrication process variations. Existing techniques…

Numerical Analysis · Mathematics 2018-12-06 Chunfeng Cui , Zheng Zhang