Explanipedia

2D electron density profile evolution during detachment in Super-X divertor L-mode discharges on MAST-U Open

N. Lonigro, R. Doyle, K. Verhaegh, B. Lipschultz, D. Moulton , et al. · 2025

The improved performance of the long-legged alternative divertor configurations on MAST-U, combining strong baffling and total flux expansion, results in stronger power and momentum losses. These lead to lower electron temperatures and pea…

Double-null power-sharing dynamics in MAST-U Open

B. Kool, Thomas Marinus van den Doel, Gijs Derks, S. Henderson, J. Lovell , et al. · 2025

Maintaining an effective double-null (DN) configuration is expected to be challenging in reactor-scale tokamak devices. As divertor power-sharing is closely linked to the magnetic topology, even minor variations can lead to fast power-shar…

Demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors Open

B. Kool, K. Verhaegh, Gijs Derks, T. Wijkamp, J.T.W. Koenders , et al. · 2025

Nuclear fusion could offer clean, abundant energy. However, managing the power exhausted from the core fusion plasma towards the reactor wall remains a major challenge. This is compounded in emerging compact reactor designs promising more …

An upper pressure limit for low-<i>Z</i> benign termination of runaway electron beams in TCV Open

Hoppe M, J. Decker, U. Sheikh, S. Coda, C. Colandrea , et al. · 2025

We present a model for the particle balance in the post-disruption runaway electron plateau phase of a tokamak discharge. The model is constructed with the help of, and applied to, experimental data from TCV discharges investigating the so…

From MAST-U to STEP: a power exhaust control strategy Open

B. Kool, M. Lennholm, A. Parrot, Paulo Soares Figueiredo, Gijs Derks , et al. · 2025

An upper pressure limit for low-Z benign termination of runaway electron beams in TCV Open

M. Hoppe, J. Decker, U. Sheikh, S. Coda, C. Colandrea , et al. · 2024

We present a model for the particle balance in the post-disruption runaway electron plateau phase of a tokamak discharge. The model is constructed with the help of, and applied to, experimental data from TCV discharges investigating the so…

Validating reduced models for detachment onset and reattachment times on MAST-U Open

S. Henderson, M. Bernert, D. Brida, Gijs Derks, S. Elmore , et al. · 2024

Two reduced models for predicting detachment onset and divertor reattachment times are validated on MAST Upgrade (MAST-U). These models are essential for future tokamak reactor design, providing rapid calculations based primarily on engine…

2D electron density profile evolution during detachment in Super-X divertor L-mode discharges on MAST-U Open

N. Lonigro, R.S. Doyle, K. Verhaegh, B. Lipschultz, D. Moulton , et al. · 2024

2D electron density profiles obtained from coherence imaging spectroscopy in different MAST-U divertor conditions are compared. The data includes variations of strike point position, core electron density, and heating power. The improved p…

First demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors Open

B. Kool, K. Verhaegh, Gijs Derks, T. Wijkamp, J.T.W. Koenders , et al. · 2024

Nuclear fusion could offer clean, abundant energy. However, managing the power exhausted from the core fusion plasma towards the reactor wall remains a major challenge, compounded in emerging compact reactor designs promising more cost-eff…

Expulsion of runaway electrons using ECRH in the TCV tokamak Open

J. Decker, Hoppe M, U. Sheikh, B.P. Duval, G. Papp , et al. · 2024

Runaway electrons (REs) are a concern for tokamak fusion reactors from discharge startup to termination. A sudden localized loss of a multi-megaampere RE beam can inflict severe damage to the first wall. Should a disruption occur, the exis…

First demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors Open

B. Kool, K. Verhaegh, Gianne Derks, T. Wijkamp, N. Lonigro , et al. · 2024

Nuclear fusion could offer clean, abundant energy. However, managing the immense power exhausted from the core fusion plasma towards the divertor remains a major challenge. This is compounded in emerging compact reactor designs which promi…

First 2D electron density measurements using Coherence Imaging Spectroscopy in the MAST-U Super-X divertor Open

N. Lonigro, R. Doyle, J. S. Allcock, B. Lipschultz, K. Verhaegh , et al. · 2024

2D profiles of electron density and neutral temperature are inferred from multi-delay Coherence Imaging Spectroscopy data of divertor plasmas using a non-linear inversion technique. The inference is based on imaging the spectral line-broad…

Expulsion of runaway electrons using ECRH in the TCV tokamak Open

J. Decker, M. Hoppe, U. Sheikh, B.P. Duval, G. Papp , et al. · 2024

Runaway electrons (REs) are a concern for tokamak fusion reactors from discharge startup to termination. A sudden localized loss of a multi-megaampere RE beam can inflict severe damage to the first wall. Should a disruption occur, the exis…

Demonstration of a sparse sensor placement technique to the limited diagnostic set in a fusion power plant Open

Joost Raukema, T.O.S.J. Bosman, I. G. J. Classen, T. Wijkamp, A. Perek , et al. · 2024

DEMO will have a limited diagnostic set for optimization of reactor performance, and limited diagnostic coverage due to challenging reactor conditions. This poses challenges for control, especially for detachment control which is planned t…

Benign termination of runaway electron beams on ASDEX Upgrade and TCV Open

U. Sheikh, J. Decker, M. Hoppe, M Pedrini, B. Sieglin , et al. · 2024

This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that a low electron density ( n e ) companion plasma was required to achieve a larg…

Initial Fulcher band observations from high resolution spectroscopy in the MAST-U divertor Open

N Osborne, K. Verhaegh, M.D. Bowden, T. Wijkamp, N. Lonigro , et al. · 2023

High resolution Fulcher band spectroscopy was used in the MAST-U divertors during Super-X and (shorter-legged) elongated divertor density ramps with fuelling from the mid-plane high-field side. In the Super-X case, the upper …

Resonant interaction between runaway electrons and the toroidal magnetic field ripple in TCV Open

T. Wijkamp, M. Hoppe, J. Decker, B.P. Duval, A. Perek , et al. · 2023

This work explains the anomalously high runaway electron (RE) pitch angles inferred in the flat-top of dedicated Tokamak à Configuration Variable (TCV) experiments. Kinetic modelling shows that the resonant interaction between the gyromoti…

Investigations of atomic \& molecular processes of NBI-heated discharges in the MAST Upgrade Super-X divertor with implications for reactors Open

K. Verhaegh, J. Harrison, B. Lipschultz, N. Lonigro, Stijn Kobussen , et al. · 2023

This experimental study presents an in-depth investigation of the performance of the MAST-U Super-X divertor during NBI-heated operation (up to 2.5 MW) focussing on volumetric ion sources and sinks as well as power losses during detachment…

Divertor shaping with neutral baffling as a solution to the tokamak power exhaust challenge Open

K. Verhaegh, J. Harrison, D. Moulton, B. Lipschultz, N. Lonigro , et al. · 2023

Exhausting power from the hot fusion core to the plasma-facing components is one of the biggest challenges in fusion energy. The MAST Upgrade tokamak uniquely integrates strong containment of neutrals within the exhaust area (divertor) wit…

The role of plasma–atom and molecule interactions on power & particle balance during detachment on the MAST Upgrade Super-X divertor Open

K. Verhaegh, B. Lipschultz, J.R. Harrison, Federici F, D. Moulton , et al. · 2023

This paper shows first quantitative analysis of the detachment processes in the MAST Upgrade Super-X divertor (SXD). We identify an unprecedented impact of plasma-molecular interactions involving molecular ions (likely ), resulting in…

Initial Fulcher band observations from high resolution spectroscopy in the MAST-U divertor Open

Nicholas J. Osborne, K. Verhaegh, M. Bowden, T. Wijkamp, N. Lonigro , et al. · 2023

High resolution Fulcher band spectroscopy was used in the MAST-U divertors during Super-X and elongated conventional divertor density ramps with $\text{D}_{2}$ fuelling from the mid-plane high-field side. In the Super-X case (density ramp …

The role of plasma-atom and molecule interactions on power \& particle balance during detachment on the MAST Upgrade Super-X divertor Open

K. Verhaegh, B. Lipschultz, J. Harrison, F. Federici, D. Moulton , et al. · 2023

This paper shows first quantitative analysis of the detachment processes in the MAST Upgrade Super-X divertor (SXD). We identify an unprecedented impact of plasma-molecular interactions involving molecular ions (likely $D_2^+$), resulting …

The X-Point radiating regime at ASDEX Upgrade and TCV Open

M. Bernert, S. Wiesen, O. Février, A. Kallenbach, J.T.W. Koenders , et al. · 2023

Future fusion reactors require a safe, steady-state divertor operation. With deep divertor detachment, which is typically induced by impurity seeding, the radiation concentrates in a small region at the X-point or on closed flux surfaces a…

Validation of 2D Te and ne measurements made with Helium imaging spectroscopy in the volume of the TCV divertor Open

B.L. Linehan, A. Perek, B.P. Duval, F Bagnato, P. Blanchard , et al. · 2023

Multi-spectral imaging of helium atomic emission (HeMSI) has been used to create 2D poloidal maps of and in TCV’s divertor. To achieve these measurements, TCV’s MANTIS multispectral cameras (Perek et al 2019 Rev. Sci. Instr…

Demonstration of a Sparse Sensor Placement Technique to the Limited Diagnostic Set in a Fusion Power Plant Open

Joost Raukema, Thomas Bosman, I. G. J. Classen, T. Wijkamp, A. Perek , et al. · 2023

Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor Open

K. Verhaegh, B. Lipschultz, J. Harrison, Nicholas J. Osborne, Aelwyn Williams , et al. · 2022

We present the first analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor using divertor spectroscopy data. Our analysis indicates detachment in the MAST-U Super-X divertor can be separate…

Runaway electron synchrotron radiation in a vertically translated plasma Open

M. Hoppe, G. Papp, T. Wijkamp, A. Perek, J. Decker , et al. · 2020

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 experimental synchrotron ima…

Experimental studies of the arc chamber short circuit failure mechanism on the DIII-D neutral beam system Open

B. Crowley, Jasper P. Beckers, Marielena Velasco Enriquez, R. Jaspers, J. Rauch , et al. · 2019

Anomalous direction for skyrmion bubble motion Open

Fanny C. Ummelen, T. Wijkamp, Tom Lichtenberg, R. A. Duine, B. Koopmans , et al. · 2018

Magnetic skyrmions are localized topological excitations that behave as particles and can be mobile, with great potential for novel data storage devices. In this work, the current-induced dynamics of large skyrmion bubbles is studied. When…

T. Wijkamp YOU? Author Swipe