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Related papers: Simulation of Edge Localised Modes using BOUT++

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A triggering mechanism responsible for the explosive onset of edge localised modes (ELMs) in fusion plasmas is identified by performing, for the first time, non-linear magnetohydrodynamic simulations of repetitive type-I ELMs. Briefly prior…

Electrochemical and equivalent-circuit modelling are the two most popular approaches to battery simulation, but the former is computationally expensive and the latter provides limited physical insight. A theoretical middle ground would be…

Chemical Physics · Physics 2020-06-05 Valentin Sulzer , S. Jon Chapman , Colin P. Please , David A. Howey , Charles W. Monroe

We use the non-linear reduced-MHD code JOREK to study ELMs in the geometry of the ASDEX Upgrade tokamak. Toroidal mode numbers, poloidal filament sizes, and radial propagation speeds of filaments into the scrape-off layer are in good…

Based on a microscopic evaluation of the local current density, a treatment of edge magnetoplasmons (EMP) is presented for confining potentials that allow Landau level (LL) flattening to be neglected. Mode damping due to electron-phonon…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 O. G. Balev , P. Vasilopoulos

An analytic theory of edge localized mode (ELM) suppression in an H-mode tokamak plasma via the application of a static, externally generated, resonant magnetic perturbation (RMP) is presented. This theory is based on the plausible…

Plasma Physics · Physics 2019-09-20 Richard Fitzpatrick

Edge plasma density fluctuations are shown to have a significant effect on the electron cyclotron resonance heating (ECRH) beam in the DIII-D tokamak. Experimental measurements of the ECRH deposition profile have been taken in three…

In low-collisionality scenarios exhibiting mitigation of edge localized modes (ELMs), stable ideal kink modes at the edge are excited by externally applied magnetic perturbation (MP)-fields. In ASDEX Upgrade these modes can cause…

Several analysis methods for nonstationary fluctuations are described and applied to the edge localized mode (ELM) instabilities of limiter H-mode plasmas. The microwave scattering diagnostic observes poloidal $k_{\theta}$ values of 3.3…

Plasma Physics · Physics 2019-11-19 Kurt S. Riedel , Alexander Sidorenko , Norton Bretz , David J. Thomson

We develop a new, efficient, and accurate method to simulate frequency-domain borehole electromagnetic (EM) measurements acquired in the presence of three-dimensional (3D) variations of the anisotropic subsurface conductivity. The method is…

Injecting frozen deuterium pellets into an ELMy H-mode plasma is a well established scheme for triggering edge localized modes (ELMs) before they naturally occur. Based on an ASDEX Upgrade H-mode plasma, this article presents a comparison…

Sustained ELM mitigation has been achieved using RMPs with a toroidal mode number of n=4 and n=6 in lower single null and with n=3 in connected double null plasmas on MAST. The ELM frequency increases by up to a factor of eight with a…

Magnetic fields in the intra-cluster medium of galaxy clusters have been studied in the past years through different methods. In the next years the up-coming generation of radio telescopes is going to provide new data that have the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 A. Bonafede , K. Dolag , F. Stasyszyn , G. Murante , S. Borgani

Edge-Localized-Mode (ELM) suppression by resonant magnetic perturbations (RMPs) generally occurs over very narrow ranges of the plasma current (or magnetic safety factor q95) in the DIII-D tokamak. However, wide q95 ranges of ELM…

Plasma Physics · Physics 2020-08-03 Q. M. Hu , R. Nazikian , B. A. Grierson , N. C. Logan , D. M. Orlov , C. Paz-Soldan , Q. Yu

The Large Eddy Simulation (LES) approach - solving numerically the large scales of a turbulent system and accounting for the small-scale influence through a model - is applied to nonlinear gyrokinetic systems that are driven by a number of…

Plasma Physics · Physics 2015-06-18 A. Bañón Navarro , B. Teaca , F. Jenko , G. W. Hammett , T. Happel , the ASDEX Upgrade Team

Training energy-based models (EBMs) on discrete spaces is challenging because sampling over such spaces can be difficult. We propose to train discrete EBMs with energy discrepancy (ED), a novel type of contrastive loss functional which only…

Machine Learning · Statistics 2023-07-18 Tobias Schröder , Zijing Ou , Yingzhen Li , Andrew B. Duncan

The development of small- and no-ELM regimes for ITER is a high priority topic due to the risks associated to type-I ELMs. By considering non-linear extended MHD simulations of the ASDEX Upgrade tokamak with the JOREK code, we probe a…

Resonant magnetic perturbations (RMPs) can mitigate the edge-localized modes (ELMs), i.e. cause a change of the ELM character towards smaller energy loss and higher frequency. During mitigation a change of the spatial structure of ELM loads…

Model-based offline reinforcement learning is brittle under distribution shift: policy improvement drives rollouts into state--action regions weakly supported by the dataset, where compounding model error yields severe value overestimation.…

Machine Learning · Computer Science 2026-02-04 Zeyu Fang , Zuyuan Zhang , Mahdi Imani , Tian Lan

We propose a new model suitable for a nonequilibrium molecular dynamics (MD) simulation of electrical conductors. The model consists of classical electrons and atoms. The atoms compose a lattice vibration system. The electrons are scattered…

Statistical Mechanics · Physics 2015-05-30 Fan Lee , Tatsuro Yuge , Akira Shimizu

In recent years simulations of chemistry and condensed materials has emerged as one of the preeminent applications of quantum computing, offering an exponential speedup for the solution of the electronic structure for certain strongly…

Quantum Physics · Physics 2022-01-19 Torin F. Stetina , Anthony Ciavarella , Xiaosong Li , Nathan Wiebe