80 citations · 1.2k across the 62 of their papers we have counts for
62 papers
An analytical criterion for significant runaway electron generation in activated tokamaks
Björn Zaar, István Pusztai, Ida Ekmark +1
A disrupting plasma in a high-performance tokamak such as ITER or SPARC may generate large runaway electron currents that, upon impact with the tokamak wall, can cause serious dama…
Batch Bayesian optimization of attosecond betatron pulses from laser wakefield acceleration
Dominika Maslarova, Albert Hansson, Mufei Luo +4
Laser wakefield acceleration can generate a femtosecond-scale broadband X-ray betatron radiation pulse from electrons accelerated by an intense laser pulse in a plasma. The microme…
Runaway electron generation in disruptions mitigated by deuterium and noble gas injection in SPARC
I. Ekmark, M. Hoppe, R. A. Tinguely +3
One of the critical challenges in future high current tokamaks is the avoidance of runaway electrons during disruptions. Here, we investigate disruptions mitigated with combined de…
Eulerian and Lagrangian electron energization during magnetic reconnection
Konrad Steinvall, Louis Richard, Tünde Fülöp +2
Electron energization by magnetic reconnection has historically been studied in the Lagrangian guiding-center framework. Insights from such studies include that Fermi acceleration…
The effect of plasmoid drifts on the pellet rocket effect in magnetic confinement fusion plasmas
N. J. Guth, O. Vallhagen, P. Helander +4
We detail here a semi-analytical model for the pellet rocket effect, which describes the acceleration of pellets in a fusion plasma due to asymmetries in the heat flux reaching the…
Control of autoresonant plasma beat-wave wakefield excitation
M. Luo, C. Riconda, I. Pusztai +3
Autoresonant phase-locking of the plasma wakefield to the beat frequency of two driving lasers offers advantages over conventional wakefield acceleration methods, since it requires…
Runaway Electron Dynamics in ITER Disruptions with Shattered Pellet Injections
Oskar Vallhagen, Lise Hanebring, Javier Artola +6
This study systematically explores the parameter space of disruption mitigation through shattered pellet injection in ITER with a focus on runaway electron dynamics, using the disr…
Drift of ablated material after pellet injection in a tokamak
O. Vallhagen, I. Pusztai, P. Helander +2
Pellet injection is used for fuelling and controlling discharges in tokamaks, and it is foreseen in ITER. During pellet injection, a movement of the ablated material towards the lo…
Parametric scaling of power exhaust in EU-DEMO alternative divertor simulations
A. E. Järvinen, L. Aho-Mantila, T. Lunt +3
Investigations of parametric scaling of power exhaust in the alternative divertor configuration (ADC) SOLPS-ITER simulation database of the EU-DEMO are conducted and compared to pr…
Runaway dynamics in reactor-scale spherical tokamak disruptions
E. Berger, I. Pusztai, S. L. Newton +4
Understanding generation and mitigation of runaway electrons in disruptions is important for the safe operation of future tokamaks. In this paper we investigate runaway dynamics in…
Bayesian approach for validation of runaway electron simulations
Aaro Järvinen, Tünde Fülöp, Eero Hirvijoki +3
Plasma-terminating disruptions in future fusion reactors may result in conversion of the initial current to a relativistic runaway electron beam. Validated predictive tools are req…
Runaway electron generation during tokamak start-up
M. Hoppe, I. Ekmark, E. Berger +1
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 i…
Attosecond dispersion as a diagnostics tool for solid-density laser-generated plasmas
Andréas Sundström, István Pusztai, Per Eng-Johnsson +1
Extreme-ultraviolet pulses can propagate through ionised solid-density targets, unlike optical pulses and, thus, have the potential to probe the interior of such plasmas on sub-fem…
Effect of Two-Stage Shattered Pellet Injection on Tokamak Disruptions
O. Vallhagen, I. Pusztai, M. Hoppe +2
An effective disruption mitigation system in a tokamak reactor should limit the exposure of the wall to localized heat losses and to the impact of high current runaway electron bea…
The hot-tail runaway seed landscape during the thermal quench in tokamaks
Ida Svenningsson, Ola Embreus, Mathias Hoppe +2
Runaway electron populations seeded from the hot-tail generated by the rapid cooling in plasma-terminating disruptions are a serious concern for next-step tokamak devices such as I…
DREAM: a fluid-kinetic framework for tokamak disruption runaway electron simulations
M. Hoppe, O. Embreus, 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 descr…
Modelling of runaway electron dynamics during argon-induced disruptions in ASDEX Upgrade and JET
K. Insulander Björk, O. Vallhagen, G. Papp +7
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 gen…
Effects of magnetic perturbations and radiation on the runaway avalanche
P. Svensson, O. Embreus, S. L. Newton +3
The electron runaway phenomenon in plasmas depends sensitively on the momentum-space dynamics. However, efficient simulation of the global evolution of systems involving runaway el…
Multimillijoule terahertz radiation from laser interactions with microplasma-waveguides
Ke Hu, Longqing Yi, Tünde Fülöp
When a relativistic, femtosecond laser pulse enters a waveguide, the pulse energy is coupled into waveguide optical modes. The longitudinal laser field effectively accelerates elec…
Assessing energy dependence of the transport of relativistic electrons in perturbed magnetic fields with orbit-following simulations
Konsta Särkimäki, Ola Embreus, Eric Nardon +2
Experimental observations, as well as theoretical predictions, indicate that the transport of energetic electrons decreases with energy. This reduction in transport is attributed t…
Attosecond betatron radiation pulse train
Vojtěch Horný, Miroslav Krůs, Tünde Fülop
High-intensity X-ray sources are essential diagnostic tools for science, technology and medicine. Such X-ray sources can be produced in laser-plasma accelerators, where electrons e…
Runaway dynamics in the DT phase of ITER operations in the presence of massive material injection
O. Vallhagen, O Embreus, I Pusztai +2
A runaway avalanche can result in a conversion of the initial plasma current into a relativistic electron beam in high current tokamak disruptions. We investigate the effect of mas…
Runaway electron synchrotron radiation in a vertically translated plasma
M. Hoppe, G. Papp, T. Wikjamp +6
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 loc…
Evaluation of the Dreicer runaway generation rate in the presence of high-Z impurities using a neural network
L Hesslow, L Unnerfelt, O Vallhagen +4
Integrated modelling of electron runaway requires computationally expensive kinetic models that are self-consistently coupled to the evolution of the background plasma parameters.…