English
Related papers

Related papers: Off-axis runaway-electron seed formation, growth a…

200 papers

Disruptions in tokamak plasmas may lead to the generation of runaway electrons that have the potential to damage plasma-facing components. Improved understanding of the runaway generation process requires interpretative modelling of…

Runaways are suprathermal electrons having sufficiently high energy to be continuously accelerated up to tens of MeV by a driving electric field [1]. Highly energetic runaway electron (RE) beams capable of damaging the tokamak first wall…

Plasma Physics · Physics 2018-08-14 Cristian Sommariva , Eric Nardon , Peter Beyer , Matthias Hoelzl , Guido Huijsman

In [V.A. Izzo et al 2022 Nucl. Fusion 62 096029], state-of-the-art modeling of thermal and current quench (CQ) MHD coupled with a self-consistent evolution of runaway electron (RE) generation and transport showed that a non-axisymmetric (n…

The disruption and runaway electron analysis model code was extended to include tungsten impurities in disruption simulations with the aim of studying the runaway electron (RE) generation. This study investigates RE current sensitivity on…

Tokamak start-up is characterized by low electron densities and strong electric fields, in order to quickly raise the plasma current and temperature, allowing the plasma to fully ionize and magnetic flux surfaces to form. Such conditions…

Plasma Physics · Physics 2022-06-30 M. Hoppe , I. Ekmark , E. Berger , T. Fülöp

Avoidance of the harmful effects of runaway electrons (REs) in plasma-terminating disruptions is pivotal in the design of safety systems for magnetic fusion devices. Here, we describe a computationally efficient numerical tool, that allows…

Plasma Physics · Physics 2021-08-11 M. Hoppe , O. Embreus , T. Fülöp

Runaway electrons (REs) generated during disruption events in tokamaks can carry mega-Ampere level currents, potentially causing damage to plasma-facing components. Understanding RE evolution during disruption events is important for…

Plasma Physics · Physics 2025-03-25 R. Datta , C. Clauser , N. Ferraro , C. Liu , R. Sweeney , R. A. Tinguely

Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the…

Plasma Physics · Physics 2015-02-26 G. I. Pokol , A. Kómár , A. Budai , A. Stahl , T. Fülöp

Accurate modeling of runaway electron generation and losses during tokamak disruptions is crucial for the development of reactor-scale tokamak devices. In this paper we present a reduced model for runaway electron losses due to flux surface…

Plasma Physics · Physics 2024-10-07 Oskar Vallhagen , Lise Hanebring , Tünde Fülöp , Mathias Hoppe , Istvan Pusztai

The operation of a 3D coil--passively driven by the current quench loop voltage--for the deconfinement of runaway electrons is modeled for disruption scenarios in the SPARC and DIII-D tokamaks. Nonlinear MHD modeling is carried out with the…

Runaway electrons (REs) present a high-priority issue for ITER but little is known about the extent to which RE generation is affected by the stochastic field intrinsic to disrupting plasmas. RE generation can be modelled with reduced…

Plasma Physics · Physics 2022-07-06 Konsta Särkimäki , Javier Artola , Matthias Hoelzl

Helicon waves satisfying the normal wave-particle cyclotron resonance are observed to limit the growth and maximum energy of relativistic electrons (REs) in low-density Ohmic DIII-D tokamak plasmas. Following the application of helicon…

We investigate the effects of runaway electron current on the dispersion relation of resistive magnetohydrodynamic modes in tokamaks. We present a new theoretical model to derive the dispersion relation, which is based on the asymptotic…

Beams of energetic runaway electrons are generated during disruptions in tokamaks, and fluid models are used to study their effects on macroscale dynamics. Linear computations of a massless, runaway electron beam coupled to MHD plasma show…

Plasma Physics · Physics 2023-08-24 A. P. Sainterme , C. R. Sovinec

Disruption-generated runaway electrons (RE) present an outstanding issue for ITER. The predictive computational studies of RE generation rely on orbit-averaged computations and, as such, they lack the effects from the magnetic field…

Plasma Physics · Physics 2017-01-19 Konsta Särkimäki , Eero Hirvijoki , Joan Decker , Jari Varje , Taina Kurki-Suonio

The potential formation of multi-mega-ampere beams of relativistic "runaway" electrons (REs) during sudden terminations of tokamak plasmas poses a significant challenge to the tokamak's development as a fusion energy source. Here, we use…

The transition of the Divertor Tokamak Test (DTT) facility from its initial commissioning phase (Day-0, plasma current $I_{p}=2$ MA) to the full power scenario ($I_{p}=5.5$ MA) introduces a critical shift in the dynamics of runaway…

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 formation of a substantial post-disruption runaway electron current in ASDEX Upgrade material injection experiments is determined by avalanche multiplication of a small seed population of runaway electrons. For the investigation of…

To make full use of photocathode material and improve its quantum efficiency lifetime, it can be necessary to operate laser away from the cathode center in photoinjectors. In RF guns, the off-axis emitted beam will see a time-dependent RF…

Accelerator Physics · Physics 2016-12-21 Rui-Xuan Huang , Chad Mitchell , Qi-Ka Jia , Christos Papadopoulos , Fernando Sannibale