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Related papers: Pulsed RF Schemes for Tearing Mode Stabilization

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Planar travelling waves on $\mathbb R^d,$ with $ d\geq 2,$ are shown to persist in systems of reaction-diffusion equations with multiplicative noise on significantly long timescales with high probability, provided that the wave is orbitally…

Analysis of PDEs · Mathematics 2025-04-15 Mark van den Bosch , Hermen Jan Hupkes

Microturbulence can produce stationary fine-scale radial corrugations on the plasma density and temperature gradients in magnetic confinement fusion devices. We show that these structures play a significant role in regulating turbulent…

Plasma Physics · Physics 2025-07-22 Ajay C. J , M. J. Pueschel , Justin Ball , David Hatch , Tobias Goerler , Stephan Brunner

Theoretical studies have suggested that nonlinear effects can lead to "radio frequency condensation", which coalesces RF power deposition and driven current near the center of a magnetic island. It is predicted that an initially broad…

In nonlinear microresonators driven by continuous-wave (cw) lasers, Turing patterns have been studied in the formalism of Lugiato-Lefever equation with emphasis on its high coherence and exceptional robustness against perturbations.…

Type-I Edge Localised Modes (ELMs) have been mitigated in MAST through the application of n = 3, 4 and 6 resonant magnetic perturbations (RMPs). For each toroidal mode number of the non-axisymmetric applied fields, the frequency of the ELMs…

New methods are developed for the stabilization of a linear system with general time-varying distributed delays existing at the system's states, inputs and outputs. In contrast to most existing literature where the function of time-varying…

Systems and Control · Electrical Eng. & Systems 2024-12-20 Qian Feng , Sing Kiong Nguang , Wilfrid Perruquetti

Electron current layers, which form in various natural and laboratory plasmas, are susceptible to multiple instabilities, with tearing being a prominent instability driven by current gradients. Tearing is considered a potential mechanism…

Plasma Physics · Physics 2025-01-27 Sushmita Mishra , Gurudatt Gaur , Bhavesh G. Patel

The ability of streamwise-travelling waves of spanwise velocity to reduce the turbulent skin friction drag is assessed in the compressible regime. Direct numerical simulations are carried out to compare drag reduction in subsonic, transonic…

This paper introduces a control strategy to simultaneously achieve asymptotic stabilization and transient frequency regulation of power networks. The control command is generated by iteratively solving an open-loop control cost minimization…

Systems and Control · Electrical Eng. & Systems 2019-11-13 Yifu Zhang , Jorge Cortes

A polarization switching pulse interleaver is shown to be effective in reducing timing noise due to polarization mode dispersion in time and frequency transfer based on mode-locked lasers and standard single-mode fibres. In closed-loop time…

By a refinement of the technique used by Johnson and Zumbrun to show stability under localized perturbations, we show that spectral stability implies nonlinear modulational stability of periodic traveling-wave solutions of reaction…

Analysis of PDEs · Mathematics 2015-05-28 Mathew Johnson , Pascal Noble , L. Miguel Rodrigues , Kevin Zumbrun

We demonstrate in a very general fashion, considerable slowing down of decoherence and relaxation by fast frequency modulation of the system heat bath coupling. The slowing occurs as the decoherence rates are now determined by the spectral…

Quantum Physics · Physics 2021-05-26 G. S. Agarwal

We demonstrate the first successful non-invasive stabilisation of nonlinear travelling waves in a straight cylindrical pipe using time-delayed feedback control (TDF) working in various symmetry subspaces. By using an approximate linear…

Fluid Dynamics · Physics 2025-02-19 Tatsuya Yasuda , Dan Lucas

The conditions for the excitation of current and voltage oscillations in the plasma of a three-electrode current and voltage stabilizer are experimentally investigated. It was found that in the regimes under consideration, the plasma has…

Plasma Physics · Physics 2021-03-03 A. S. Mustafaev , A. Yu. Grabovskiy , B. D. Klimenkov

Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density…

GTPase molecules are important regulators in cells that continuously run through an activation/deactivation and membrane-attachment/membrane-detachment cycle. Activated GTPase is able to localize in parts of the membranes and to induce cell…

Analysis of PDEs · Mathematics 2011-12-08 Andreas Rätz , Matthias Röger

In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized…

Analysis of PDEs · Mathematics 2015-05-28 Mathew Johnson , Pascal Noble , L. Miguel Rodrigues , Kevin Zumbrun

Temporal modulation unlocks possibilities to dynamically control and modify the response of electromagnetic systems. Employing explicit dependencies of circuit or surface parameters on time enables the engineering of systems with…

Systems and Control · Electrical Eng. & Systems 2023-03-01 Grigorii Ptitcyn , Mohammad Sajjad Mirmoosa , Silvi Hrabar , Sergey Tretyakov

A theoretical investigation for implementing a scheme of forced evaporative cooling in radio-frequency (rf) adiabatic potentials is presented. Supposing the atoms to be trapped by a rf field RF1, the cooling procedure is facilitated using a…

Atomic Physics · Physics 2009-11-13 Carlos L. Garrido Alzar , Hélène Perrin , Barry M. Garraway , Vincent Lorent

Recent numerical results show that if a scalar is mixed by periodically forced turbulence, the average mixing rate is directly affected for forcing frequencies small compared to the integral turbulence frequency. We elucidate this by an…

Fluid Dynamics · Physics 2016-11-04 Wouter Bos , Robert Rubinstein