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Full-f global gyrokinetic simulations of the plasma boundary have until now required heroic computational efforts and case-by-case expert intervention, precluding systematic parameter scans. Here we demonstrate a paradigm shift: hundreds of…

Plasma Physics · Physics 2026-05-18 A. C. D. Hoffmann , M. Francisquez , T. N. Bernard , G. W. Hammett , A. Hakim

Time integrated spectroscopic measurements are carried out to characterize transient plasma stream produced in a coaxial pulsed plasma accelerator. This method allows the estimation of different plasma parameters and its evolution with…

Plasma Physics · Physics 2020-08-04 A. Ahmed , S. Singha , S. Borthakur , N. K. Neog , T. K. Borthakur , J. Ghosh

We have developed an innovative workflow, STEP-0D, within the OMFIT integrated modelling framework. Through systematic validation against the International Tokamak Physics Activity (ITPA) global H-mode confinement database, we demonstrated…

In situ generation of a high-energy, high-current, spin-polarized electron beam is an outstanding scientific challenge to the development of plasma-based accelerators for high-energy colliders. In this Letter we show how such a…

A first-principles scaling law, based on turbulent transport considerations, and a multi-machine database of density limit discharges from the ASDEX Upgrade, JET and TCV tokamaks, show that the increase of the boundary turbulent transport…

Plasma Physics · Physics 2022-05-10 M. Giacomin , A. Pau , P. Ricci , O. Sauter , T. Eich

In tokamak plasmas, sheared flows perpendicular to the driving temperature gradients can strongly stabilize linear modes. While the system is linearly stable, regimes with persistent nonlinear turbulence may develop, i.e. the system is…

Plasma Physics · Physics 2019-01-16 Ben F. McMillan , Chris C. T. Pringle , Bogdan Teaca

It is shown that rapid substantial changes in heating rate can induce transitions to improved energy confinement regimes in zero-dimensional models for tokamak plasma phenomenology. We examine for the first time the effect of step changes…

Plasma Physics · Physics 2014-06-19 H. Zhu , S. C. Chapman , R. O. Dendy , K. Itoh

A challenging and fundamental research problem is the better understanding and control of the turbulent transport of heat in present-day tokamak fusion experiments. Recent developments in numerical methods along with enormous gains in…

Plasma Physics · Physics 2008-02-03 Jeremy Kepner , Scott Parker , Viktor Decyk

Massive runaway positrons are generated by runaway electrons in tokamaks. The fate of these positrons encodes valuable information about the runaway dynamics. The phase space dynamics of a runaway position is investigated using a Lagrangian…

Plasma Physics · Physics 2015-04-20 Jian Liu , Hong Qin , Nathaniel J. Fisch , Qian Teng , Xiaogang Wang

The visible camera system EDICAM (Event Detection Intelligent Camera), recently installed on JT-60SA, is simulated to assess whether it can be used for measuring synchrotron radiation from relativistic runaway electrons. In this simulation,…

Plasma Physics · Physics 2023-09-28 Soma Olasz , Mathias Hoppe , Tamás Szepesi , Kensaku Kamiya , Peter Balazs , Gergo I. Pokol

We here propose a model to capture the complexity of the streamer corona adjacent to leader stepping and relate it to the production of energetic electrons serving as a source of X-rays and $\gamma$-rays, manifesting in terrestrial…

Atmospheric and Oceanic Physics · Physics 2020-04-22 C. Köhn , O. Chanrion , K. Nishikawa , L. Babich , T. Neubert

In this paper the experimental fact of presence of ionic - sound oscillations in plasma of tokamak DIII-D is given for plasma with additional heating by means of a neutral hydrogen beam. It contradicts modern theoretical representations…

Plasma Physics · Physics 2014-05-15 V. A. Rantsev-Kartinov , A. N. Kulakov

Synchrotron radiation observed from runaway electrons (REs) in tokamaks depends upon the position and size of the RE beam, the RE energy and pitch distributions, as well as the location of the observer. We show that experimental synchrotron…

Plasma Physics · Physics 2020-08-19 M. Hoppe , G. Papp , T. Wikjamp , A. Perek , J. Decker , B. Duval , O. Embreus , T. Fülöp , U. A. Sheikh

We focus on the process of plasma acceleration in the presence of non-negligible thermal effects, wherein a driver of relativistic electrons perturbs a warm neutral plasma and generates a wakefield structure. We study the acceleration…

We propose a new and simple strategy for controlled ionization-induced trapping of electrons in a beam-driven plasma accelerator. The presented method directly exploits electric wakefields to ionize electrons from a dopant gas and capture…

Accelerator Physics · Physics 2015-06-09 A. Martinez de la Ossa , J. Grebenyuk , T. Mehrling , L. Schaper , J. Osterhoff

We investigate the ExB diffusion of fusion born \alpha particles in tokamak plasmas. We determine the transport regimes for a realistic model that has the characteristics of the ion temperature gradient (ITG) or of the trapped electron…

Plasma Physics · Physics 2017-02-01 A. Croitoru , D. I. Palade , M Vlad , F Spineanu

The study of parametric instabilities has played a crucial role in understanding energy transfer to plasma and, with that, the development of key applications such as inertial confinement fusion. When the densities are between…

We study the evolution of degenerate electron cores primarily composed of the carbon burning products oxygen, neon, and magnesium (hereafter ONeMg cores) that are undergoing compression. Electron capture reactions on A=20 and A=24 isotopes…

Solar and Stellar Astrophysics · Physics 2016-08-12 Josiah Schwab , Eliot Quataert , Lars Bildsten

The development of operational scenarios without large Type-I ELMs is of utmost importance for the stable operation and longevity of future tokamaks. The EUROfusion tokamak exploitation program has therefore made the understanding of…

The collision of two expanding plasma clouds is investigated, emphasizing instabilities and electron energization in the plasma mixing layer. This work is directly relevant to laboratory experiments with explosively-created laser or z-pinch…

Plasma Physics · Physics 2022-08-24 M. A. Malkov , V. I. Sotnikov