80 citations · 312 across the 19 of their papers we have counts for
20 papers
Runaway electron generation in ITER mitigated disruptions with improved physics models
L. Votta, F. J. Artola, E. Nardon +2
We assess runaway-electron (RE) generation in ITER disruptions mitigated by shattered pellet injection (SPI) using improved physics modelling in the 1D disruption simulation framew…
Simulation of Shattered Pellet Injections with Plasmoid Drifts in ASDEX Upgrade and ITER
O. Vallhagen, L. Antonsson, P. Halldestam +7
Pellet injection is an important means to fuel and control discharges and mitigate disruptions in reactor-scale fusion devices. To accurately assess the efficiency of these applica…
Reduced kinetic modelling of shattered pellet injection in ASDEX Upgrade
Peter Halldestam, Paul Heinrich, Gergely Papp +8
Plasma-terminating disruptions represent a critical outstanding issue for reactor-relevant tokamaks. ITER will use shattered pellet injection (SPI) as its disruption mitigation sys…
The pellet rocket effect in magnetic confinement fusion plasmas
Nico J. Guth, Oskar Vallhagen, Per Helander +3
Pellets of frozen material travelling into a magnetically confined fusion plasma are accelerated by the so-called pellet rocket effect. The non-uniform plasma heats the pellet abla…
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…
Reduced modeling of scrape-off losses of runaway electrons during tokamak disruptions
Oskar Vallhagen, Lise Hanebring, Tünde Fülöp +2
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 r…
Fluid and kinetic studies of tokamak disruptions using Bayesian optimization
Ida Ekmark, Mathias Hoppe, Tünde Fülöp +4
When simulating runaway electron dynamics in tokamak disruptions, fluid models with lower numerical cost are often preferred to more accurate kinetic models. The aim of this work i…
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…
Bayesian optimization of massive material injection for disruption mitigation in tokamaks
Istvan Pusztai, Ida Ekmark, Hannes Bergström +5
A Bayesian optimization framework is used to investigate scenarios for disruptions mitigated with combined deuterium and neon injection in ITER. The optimization cost function take…
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…
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…
Runaway dynamics in disruptions with current relaxation
István Pusztai, Mathias Hoppe, Oskar Vallhagen
The safe operation of tokamak reactors requires a reliable modeling capability of disruptions, and in particular the spatio-temporal dynamics of associated runaway electron current…
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…
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…
Kinetic modelling of runaway electron generation in argon-induced disruptions in ASDEX Upgrade
K. Insulander Björk, G. Papp, O. Embreus +8
Massive material injection has been proposed as a way to mitigate the formation of a beam of relativistic runaway electrons that may result from a disruption in tokamak plasmas. In…
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…
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.…
Effect of plasma elongation on current dynamics during tokamak disruptions
T. Fülöp, P. Helander, O. Vallhagen +6
Plasma terminating disruptions in tokamaks may result in relativistic runaway electron beams with potentially serious consequences for future devices with large plasma currents. In…
Influence of massive material injection on avalanche runaway generation during tokamak disruptions
L Hesslow, O Embréus, O Vallhagen +1
In high-current tokamak devices such as ITER, a runaway avalanche can cause a large amplification of a seed electron population. We show that disruption mitigation by impurity inje…