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Remarkable progress has been made in diagnosing energetic particle instabilities on present-day machines and in establishing a theoretical framework for describing them. This overview describes the much improved diagnostics of Alfven…

In this letter, an initially unmagnetized pair plasma with asymmetric velocity distributions is investigated where any unstable Weibel mode must be isolated, with discrete values for the growth rates and the unstable wavenumbers. For both a…

Astrophysics · Physics 2013-06-25 R. C. Tautz , I. Lerche

Confinement phenomenology characteristic of magnetically confined plasmas emerges naturally from a simple sandpile algorithm when the parameter controlling redistribution scalelength is varied. Close analogues are found for enhanced…

Plasma Physics · Physics 2009-11-06 S. C. Chapman , R. O. Dendy , B. Hnat

Intermittent fluctuations in the boundary of magnetically confined plasmas are investigated by numerical turbulence simulations of a reduced fluid model describing the evolution of the plasma density and electric drift vorticity in the…

Recent progress on studies of the nanoscale mechanical responses in disordered systems has highlighted a strong degree of heterogeneity in the elastic moduli. In this contribution, using computer simulations, we study the elastic…

Soft Condensed Matter · Physics 2016-02-12 Hideyuki Mizuno , Leonardo E. Silbert , Matthias Sperl

A global signature of the build-up to an intrinsic ELM is found in the phase of signals measured in full flux azimuthal loops in the divertor region of JET. Full flux loop signals provide a global measurement proportional to the voltage…

Nonparametric maximum likelihood estimators (MLEs) in inverse problems often have non-normal limit distributions, like Chernoff's distribution. However, if one considers smooth functionals of the model, with corresponding functionals of the…

Statistics Theory · Mathematics 2023-10-24 Piet Groeneboom

The Weibel instability driven by two symmetric counter-streaming relativistic electron plasmas, also referred to as current-filamentation instability, is studied in a constant and uniform external magnetic field aligned with the plasma…

Plasma Physics · Physics 2017-02-08 A. Grassi , M. Grech , F. Amiranoff , F. Pegoraro , A. Macchi , C. Riconda

We report on numerical simulation studies of the dynamical behavior of edge localized modes (ELMs) under the influence of repetitive injection of pellets. In our nonlinear 2-fluid model the ELMs are excited by introducing a particle source…

Plasma Physics · Physics 2019-07-24 D Chandra , A Sen , A Thyagaraja

The emergence and dynamics of filamentary structures associated with edge-localized modes (ELMs) inside tokamak plasmas during high-confinement mode is regularly studied using Electron Cyclotron Emission Imaging (ECEI) diagnostic systems.…

Plasma Physics · Physics 2022-04-05 Cooper Jacobus , Minjun J. Choi , Ralph Kube

We extend collisional quantum thermometry schemes to allow for stochasticity in the waiting time between successive collisions. We establish that introducing randomness through a suitable waiting time distribution, the Weibull distribution,…

Quantum Physics · Physics 2021-12-15 Eoin O'Connor , Bassano Vacchini , Steve Campbell

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…

Tokamak operational regimes with small edge localized modes (ELMs) could be a solution to the problem of large transient heat loads in future fusion reactors because they provide quasi-continuous exhaust while keeping a good plasma…

We present that a statistical method known as the Complexity-Entropy analysis is useful to characterize a state of plasma turbulence and flux in the resonant magnetic perturbation (RMP) edge localized mode (ELM) control experiment. The RMP…

We study the statistical distribution of components in the non-perturbative parts of energy eigenfunctions (EFs), in which main bodies of the EFs lie. Our numerical simulations in five models show that deviation of the distribution from the…

Quantum Physics · Physics 2016-08-24 Jiaozi Wang , Wen-ge Wang

In H-mode tokamak plasmas, the plasma is sometimes ejected beyond the edge transport barrier. These events are known as edge localized modes (ELMs). ELMs cause a loss of energy and damage the vessel walls. Understanding the physics of ELMs…

Plasma Physics · Physics 2024-07-08 N. Q. X. Teo , V. H. Hall-Chen , K. Barada , R. J. H. Ng , L. Gu , A. K. Yeoh , Q. T. Pratt , X. Garbet , T. L. Rhodes

Recently, it has been proposed that the turbulent fluctuations measured in a linear plasma device could be described as a superposition of uncorrelated Lorentzian pulses with a narrow distribution of durations, which would provide an…

Plasma Physics · Physics 2012-09-11 B. Ph. van Milligen , R. Sánchez , C. Hidalgo

The statistical properties of the $E \times B$ flux in different types of plasma turbulence simulations are investigated using probability density distribution functions (PDF). The physics included in the models ranges from two dimensional…

Plasma Physics · Physics 2009-11-10 Volker Naulin , Odd Erik Garcia , Anders Henry Nielsen , Jens Juul Rasmussen

We study electromagnetic streaming instabilities in thermal viscous regions of rotating astrophysical objects, such as, magnetized accretion disks, molecular clouds, their cores, and elephant trunks. The obtained results can also be applied…

Astrophysics of Galaxies · Physics 2015-05-14 Anatoly Nekrasov

The temporal evolution of the magnetic field associated with electron thermal Weibel instability in optical-field ionized plasmas is measured using ultrashort (1.8 ps), relativistic (45 MeV) electron bunches from a linear accelerator. The…