Publications by Holger Reimerdes

Overview of the third JET deuterium-tritium campaign

Olivier Sauter, Holger Reimerdes, Benoît Labit

JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET’s 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-dept ...

2025

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

Basil Duval, Holger Reimerdes, Stefano Coda, Joan Decker, Umar Sheikh, Claudia Colandrea, Luke Simons

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-called 'low-Z be ...

IOP Publishing Ltd2025

Investigating the influence of divertor baffles on nitrogen-seeded detachment in TCV with SOLPS-ITER simulations and TCV experiments

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Olivier Claude Martin Février, Sophie Danielle Angelica Gorno, Claudia Colandrea, Guang-Yu Sun, Luke Simons

Plasma edge simulations with the SOLPS-ITER code are performed to study the influence of divertor baffles on nitrogen-seeded detachment in Tokamak & agrave; Configuration Variable (TCV) single-null, L-mode discharges. Scans of nitrogen seeding rate are con ...

IOP Publishing Ltd2025

Neutral pressure measurement in TCV tokamak using ASDEX-type pressure gauges

Holger Reimerdes, Marcelo Baquero Ruiz, Guang-Yu Sun

Probing the neutral gas distribution at the edge of magnetic confinement fusion devices is critical for plasma exhaust studies. In the TCV tokamak, a set of ASDEX-type hot ionization pressure gauges (APGs) has been installed for fast, in situ measurements ...

2025

X-point radiation: From discovery to potential application in a future reactor

Holger Reimerdes, Christian Gabriel Theiler, Umar Sheikh, Olivier Claude Martin Février

Power exhaust is a crucial issue for future fusion reactors. Divertor detachment and the required power dissipation fractions of about 95% are foreseen to be achieved by impurity seeding. In a tokamak, at high seeding levels the radiation often concentrate ...

Elsevier2025

𝑋-Point Target Radiator Regime in Tokamak Divertor Plasmas

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Curdin Tobias Wüthrich, Garance Hélène Salomé Durr-Legoupil-Nicoud, Daniele Hamm, Sophie Danielle Angelica Gorno, Francesco Pastore, Luke Simons, Artur Perek

Fusion plasma regimes with a strongly radiating magnetic 𝑋 point are promising candidates to tackle the outstanding power exhaust challenge in reactor-scale devices. In this Letter, we report on a new type of 𝑋-point radiator, the XPTR (𝑋-point target radi ...

American Physical Society (APS)2025

Effect of energetic ions on edge-localized modes in tokamak plasmas

Patrick Blanchard, Timothy Goodman, Jean-Marc Moret, Olivier Sauter, Holger Reimerdes, Stefano Coda, Alexander Karpushov, Yanis Andrebe, Duccio Testa, Benoît Labit, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Hugo De Oliveira, Claudio Marini, Antoine Pierre Emmanuel Alexis Merle, Anna Teplukhina, Joan Decker, Cedric Kar-Wai Tsui, Umar Sheikh, Cristian Galperti, Kevin Henricus Annemarie Verhaegh, Dahye Choi, Aylwin Iantchenko, Mengdi Kong, Roberto Maurizio, Francesco Carpanese, Mirko Wensing, Lorenzo Stipani, Federico Pesamosca, Olivier Claude Martin Février, Filippo Bagnato, Cristian Sommariva, Davide Galassi

The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is the high-confinement mode. In this regime, however, periodic relaxations of the plasma edge can occur. These edge-localized modes pose a ...

2025

Divertor Shaping with Neutral Baffling as a Solution to the Tokamak Power Exhaust Challenge

Holger Reimerdes, Christian Gabriel Theiler, Olivier Claude Martin Février

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

NATURE PORTFOLIO2025

Interpretation of divertor ion temperature measurements from an attached towards a detached regime

Patrick Blanchard, Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Olivier Claude Martin Février, Lorenzo Martinelli, Sophie Danielle Angelica Gorno, Claudia Colandrea, Christine Stollberg, Luke Simons, Artur Perek

We present simultaneous profiles of the poloidal distribution of electron temperature and density (Te, ne), the poloidal emissivity distributions of a range of spectral lines together with the corresponding ion temperatures, Ti, in the TCV divertor plasma. ...

2025

X-point radiator control and its dynamics in ASDEX Upgrade and JET deuterium-tritium discharges

Holger Reimerdes

Control of heat exhaust is essential for the operation of power producing fusion reactors. Here, we present results of heat exhaust feedback control experiments in JET and AUG. In JET, we demonstrate the first X-point radiator (XPR) control in DD and DT di ...

IOP Publishing Ltd2025

Edge plasma turbulence simulations in detached regimes with the SOLEDGE3X code

Holger Reimerdes, Davide Mancini

Experimental results from several tokamaks suggest a strong impact of divertor density regimes on turbulent transport in the edge plasma. Reciprocally, the change in cross- field transport and Scrape-Off-Layer (SOL) width affects the access to density regi ...

Elsevier2024

Access to an ELM-suppressed X-point radiator regime in TCV snowflake minus configurations

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Curdin Tobias Wüthrich, Olivier Claude Martin Février, Daniele Hamm, Sophie Danielle Angelica Gorno, Guang-Yu Sun, Luke Simons, Artur Perek

TCV’s operating regime with an X-point radiator (XPR) has been broadened by changing the magnetic geometry. XPRs have properties that could make them an attractive power exhaust solution for fusion reactors. These include the conversion of a high fraction ...

Elsevier2024

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

Holger Reimerdes, Christian Gabriel Theiler

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. The particle ba ...

IOP Publishing Ltd2024

Multi-machine benchmark of the self-consistent 1D scrape-off layer model DIV1D from stagnation point to target with SOLPS-ITER

Holger Reimerdes

This paper extends a 1D dynamic physics-based model of the scrape-off layer (SOL) plasma, DIV1D, to include the core SOL and possibly a second target. The extended model is benchmarked on 1D mapped SOLPS-ITER simulations to find input settings for DIV1D th ...

Iop Publishing Ltd2024

Comparison of detachment in Ohmic plasmas with positive and negative triangularity

Basil Duval, Olivier Sauter, Holger Reimerdes, Stefano Coda, Laurie Porte, Christian Gabriel Theiler, Olivier Claude Martin Février, Garance Hélène Salomé Durr-Legoupil-Nicoud, Sophie Danielle Angelica Gorno, Claudia Colandrea, Artur Perek

In recent years, negative triangularity (NT) has emerged as a potential high-confinement L-mode reactor solution. In this work, detachment is investigated using core density ramps in lower single null Ohmic L-mode plasmas across a wide range of upper, lowe ...

Iop Publishing Ltd2024

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

Holger Reimerdes

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 engineering parameters. ...

Elsevier2024

Overview of physics results from MAST upgrade towards core-pedestal-exhaust integration

Olivier Sauter, Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Matteo Vallar, Samuele Mazzi

Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening understanding of key physics issues for the operation of ITER and the design of future fusion power plants. The impact of MHD instab ...

IOP Publishing Ltd2024

Validation of SOLPS-ITER simulations against the TCV-X21 reference case

Holger Reimerdes, Christian Gabriel Theiler, Davide Galassi, Lorenzo Martinelli, Claudia Colandrea

This paper presents a quantitative validation of Scrape-Off Layer Plasma Simulation-ITER (SOLPS-ITER) simulations against the TCV-X21 reference case and provides insights into the neutral dynamics and ionization source distribution in this scenario. TCV-X2 ...

IOP Publishing Ltd2024

X-point radiator and power exhaust control in configurations with multiple X-points in TCV

Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Curdin Tobias Wüthrich, Olivier Claude Martin Février, Garance Hélène Salomé Durr-Legoupil-Nicoud, Filippo Bagnato, Lorenzo Martinelli, Sophie Danielle Angelica Gorno, Claudia Colandrea, Guang-Yu Sun, Luke Simons, Artur Perek

Novel power exhaust solutions are being developed to address the challenge of integrating a high performance fusion core plasma with a well-protected divertor, if the single null configuration does not scale to a reactor device. This work aims to elucidate ...

American Institute of Physics (AIP)2024

Experimental research on the TCV tokamak

Patrick Blanchard, Stefano Alberti, Ambrogio Fasoli, Timothy Goodman, Yves Martin, Olivier Sauter, Henri Weisen, Ivo Furno, Holger Reimerdes, Jean-Philippe Hogge, Stefano Coda, Alexander Karpushov, Yanis Andrebe, Duccio Testa, Benoît Labit, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Jérémy Genoud, Hugo De Oliveira, Antoine Pierre Emmanuel Alexis Merle, Antoine Baillod, Joan Decker, Cedric Kar-Wai Tsui, Pedro Andres Molina Cabrera, Umar Sheikh, Cristian Galperti, Marcelo Baquero Ruiz, Aylwin Iantchenko, Mengdi Kong, Francesco Carpanese, Federico Pesamosca, Olivier Claude Martin Février, Simon Van Mulders, Nicola Offeddu, Garance Hélène Salomé Durr-Legoupil-Nicoud, Maurizio Giacomin, Filippo Bagnato, Davide Galassi, Arsène Stéphane Tema Biwole, Lorenzo Martinelli, , , , , , , , , , , , , , , , , , , , , , , ,