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Related papers: Control of stochasticity in magnetic field lines

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It is shown that a relevant control of Hamiltonian chaos is possible through suitable small perturbations whose form can be explicitly computed. In particular, it is possible to control (reduce) the chaotic diffusion in the phase space of a…

Chaotic Dynamics · Physics 2007-05-23 G. Ciraolo , F. Briolle , C. Chandre , E. Floriani , R. Lima , M. Vittot , M. Pettini , C. Figarella , P. Ghendrih

A method of chaos reduction for Hamiltonian systems is applied to control chaotic advection. By adding a small and simple term to the stream function of the system, the construction of invariant tori has a stabilization effect in the sense…

It is shown that a relevant control of Hamiltonian chaos is possible through suitable small perturbations whose form can be explicitly computed. In particular, it is possible to control (reduce) the chaotic diffusion in the phase space of a…

We review a method of control for Hamiltonian systems which is able to create smooth invariant tori. This method of control is based on an apt modification of the perturbation which is small and localized in phase space.

Chaotic Dynamics · Physics 2007-05-23 Cristel Chandre , Guido Ciraolo , Ricardo Lima , Michel Vittot

We present a method of localised control of chaos in Hamiltonian systems. The aim is to modify the perturbation locally by a small control term which makes the controlled Hamiltonian more regular. We provide an explicit expression for the…

Chaotic Dynamics · Physics 2007-05-23 Michel Vittot , Cristel Chandre , Guido Ciraolo , Ricardo Lima

We reconsider a control theory for Hamiltonian systems, that was introduced on the basis of KAM theory and applied to a model of magnetic field in previous articles. By a combination of Frequency Analysis and of a rigorous (Computer…

Dynamical Systems · Mathematics 2021-05-25 Lorenzo Valvo , Ugo Locatelli

We analyze the behavior of a relativistic particle moving under the influence of a uniform magnetic field and a stationary electrostatic wave. We work with a set of pulsed waves that allows us to obtain an exact map for the system. We also…

Chaotic Dynamics · Physics 2012-08-02 M. C. de Sousa , I. L. Caldas , F. B. Rizzato , R. Pakter , F. M. Steffens

We present a technique to control chaos in Hamiltonian systems which are close to integrable. By adding a small and simple control term to the perturbation, the system becomes more regular than the original one. We apply this technique to a…

The issue of magnetic confinement in magnetic fusion devices is addressed within a purely magnetic approach. Using some Hamiltonian models for the magnetic field lines, the dual impact of low magnetic shear is shown in a unified way. Away…

Plasma Physics · Physics 2011-03-21 Marie-Christine Firpo , Dana Constantinescu

The chaotic transport of charged particles in a turbulent electrostatic potential sets the conditions of a severe limitation to the plasma confinement in devices such as tokamaks. In this chapter, we consider the motion of impurities driven…

Chaotic Dynamics · Physics 2016-12-21 Cristel Chandre , Guido Ciraolo , Michel Vittot

We present a method to control transport in Hamiltonian systems. We provide an algorithm - based on a perturbation of the original Hamiltonian localized in phase space - to design small control terms that are able to create isolated…

Chaotic Dynamics · Physics 2007-05-23 Guido Ciraolo , Cristel Chandre , Ricardo Lima , Michel Vittot , Marco Pettini , Philippe Ghendrih

This work explores the possibility of controlling the dissociation of a monochromatically driven one-dimensional Morse oscillator by recreating barriers, in the form of invariant tori with irrational winding ratios, at specific locations in…

Chaotic Dynamics · Physics 2009-11-13 Astha Sethi , Srihari Keshavamurthy

Chaos often represents a severe obstacle for the set-up of many-body experiments, e.g., in fusion plasmas or turbulent flows. We propose a strategy to control chaotic diffusion in conservative systems. The core of our approach is a small…

Chaotic Dynamics · Physics 2007-05-23 Cristel Chandre , Guido Ciraolo , Fabrice Doveil , Ricardo Lima , Alessandro Macor , Michel Vittot

A method to reduce or enhance chaos in Hamiltonian flows with two degrees of freedom is discussed. This method is based on finding a suitable perturbation of the system such that the stability of a set of periodic orbits changes (local…

Chaotic Dynamics · Physics 2007-05-23 Romain Bachelard , Cristel Chandre , Xavier Leoncini

This study extends the functional perturbation theory~(FPT) of dynamical systems, which was initially developed for investigating the shifts of magnetic field line trajectories within the chaotic edge region of plasma when subjected to…

Chaotic Dynamics · Physics 2024-11-26 Wenyin Wei , Jiankun Hua , Alexander Knieps , Yunfeng Liang

We present a technique to control chaos in Hamiltonian systems which are close to integrable. By adding a small and simple control term to the perturbation, the system becomes more regular than the original one. We apply this technique to a…

Chaotic Dynamics · Physics 2007-05-23 G. Ciraolo , C. Chandre , R. Lima , M. Vittot , M. Pettini

A numerical and experimental study of a control method aimed at channeling chaos by building barriers in phase space is performed on a paradigm for wave-particle interaction, i.e., a traveling wave tube. Control of chaotic diffusion is…

An analysis of instability dynamics in a stochastic magnetic field is presented for the tractable case of the resistive interchange. Externally prescribed static magnetic perturbations convert the eigenmode problem to a stochastic…

Plasma Physics · Physics 2023-06-14 Mingyun Cao , P. H. Diamond

We analyze stochasticity in the magnetic fields of magnetic confinement fusion reactors by calculating the lobe areas of turnstiles - a method developed for characterizing transport into and out of resonance zones in Hamiltonian dynamical…

Plasma Physics · Physics 2025-04-16 Christopher Berg Smiet , Ludovic Rais , Joaquim Loizu , Robert Davies

Recent observations of topological spin textures brought spintronics one step closer to new magnetic memories. Nevertheless, the existence of Skyrmions, as well as their stabilization, require very specific intrinsic magnetic properties…

Mesoscale and Nanoscale Physics · Physics 2017-04-19 E. A. Stepanov , C. Dutreix , M. I. Katsnelson
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