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

B. Kool; K. Verhaegh; G.L. Derks; T.A. Wijkamp; J.T.W. Koenders; N. Lonigro; G. McArdle; C. Vincent; J. Lovell; S.S. Henderson; F. Federici; D. Brida; H. Reimerdes; N. Osborne; M. van Berkel; Tuomas Tala; Antti Snicker; Konsta Särkimäki; Antti Salmi; Jari Likonen; Adam Kit; Anu Kirjasuo; Juuso Karhunen; Aaro Järvinen; Antti Hakola; et al.; EUROfusion Tokamak Exploitation Team; MAST Upgrade Team

doi:10.1038/s41560-025-01824-7

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

B. Kool^*
, K. Verhaegh^*
, G.L. Derks
, T.A. Wijkamp
, J.T.W. Koenders
, N. Lonigro
, G. McArdle
, C. Vincent
, J. Lovell
, S.S. Henderson
, F. Federici
, D. Brida
, H. Reimerdes
, N. Osborne
, M. van Berkel
, Tuomas Tala
, Antti Snicker
, Konsta Särkimäki
, Antti Salmi
, Jari Likonen

Adam Kit, Anu Kirjasuo, Juuso Karhunen, Aaro Järvinen, Antti Hakola, et al., EUROfusion Tokamak Exploitation Team, MAST Upgrade Team

^*Corresponding author for this work

BA4511 Fusion energy

Research output: Contribution to journal › Article › Scientific › peer-review

6 Citations (Scopus)

Abstract

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 cost-effective pathways towards commercial fusion energy. Alternative Divertor Configurations (ADCs) are a potential solution. In this work, we demonstrate exhaust control in ADCs, employing a novel method to diagnose the neutral gas buffer, which shields the target. Our work on the Mega Ampere Spherical Tokamak Upgrade shows that ADCs tackle key risks and uncertainties for fusion energy. Their highly reduced sensitivity to perturbations enables active exhaust control in otherwise unfeasible situations and facilitates an increased passive absorption of transients, which would otherwise damage the divertor. We observe a strong decoupling of each divertor from other reactor regions, enabling near-independent control of the divertors and core plasma. Our work showcases the real-world benefits of ADCs for effective heat load management in fusion power reactors.

Original language	English
Pages (from-to)	1116-1131
Journal	Nature Energy
Volume	10
DOIs	https://doi.org/10.1038/s41560-025-01824-7
Publication status	Published - 2025
MoE publication type	A1 Journal article-refereed

Funding

We thank C. Theiler for his foundational contributions to the development of alternative divertors under EUROfusion. We are grateful to R. Osawa for providing the SOLPS simulation of the STEP divertor. The contribution of R. Doyle in supporting operation of the MWI diagnostic is kindly acknowledged. DIFFER is part of the institutes organization of NWO. This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (grant agreement number 101052200 - EUROfusion) (B.K., K.V., G.L.D., T.A.W., J.T.W.K., N.L., G.M., C.V., S.S.H., D.B., H.R., N.O., M.B, The EUROfusion tokamak exploitation team, the MAST-U team) and from the Engineering and Physical Sciences Research Council (EPSRC) (grant numbers EP/W006839/1, EP/T012250/1, EP/N023846/1 (K.V., G.M., C.V., S.S.H., the MAST-U team) and EP/S022430/1 (N.L., N.O., F.F.)). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI) (H.R.). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, or the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. This work was supported by the US Department of Energy under grant number DE-AC05-00OR22725 (J.L., F.F.).

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

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10.1038/s41560-025-01824-7

Cite this

Kool, B., Verhaegh, K., Derks, G. L., Wijkamp, T. A., Koenders, J. T. W., Lonigro, N., McArdle, G., Vincent, C., Lovell, J., Henderson, S. S., Federici, F., Brida, D., Reimerdes, H., Osborne, N., van Berkel, M., Tala, T., Snicker, A., Särkimäki, K., Salmi, A., ... MAST Upgrade Team (2025). Demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors. Nature Energy, 10, 1116-1131. https://doi.org/10.1038/s41560-025-01824-7

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abstract = "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 cost-effective pathways towards commercial fusion energy. Alternative Divertor Configurations (ADCs) are a potential solution. In this work, we demonstrate exhaust control in ADCs, employing a novel method to diagnose the neutral gas buffer, which shields the target. Our work on the Mega Ampere Spherical Tokamak Upgrade shows that ADCs tackle key risks and uncertainties for fusion energy. Their highly reduced sensitivity to perturbations enables active exhaust control in otherwise unfeasible situations and facilitates an increased passive absorption of transients, which would otherwise damage the divertor. We observe a strong decoupling of each divertor from other reactor regions, enabling near-independent control of the divertors and core plasma. Our work showcases the real-world benefits of ADCs for effective heat load management in fusion power reactors.",

author = "B. Kool and K. Verhaegh and G.L. Derks and T.A. Wijkamp and J.T.W. Koenders and N. Lonigro and G. McArdle and C. Vincent and J. Lovell and S.S. Henderson and F. Federici and D. Brida and H. Reimerdes and N. Osborne and \{van Berkel\}, M. and I. Zychor and M. Zurita and M. Zuin and X. Zou and Zotta, \{V. K.\} and A. Zohar and M. Zlobinski and Zimmermann, \{C. F.B.\} and P. Zestanakis and M. Zerbini and J. Zebrowski and Y. Zayachuk and D. Zarzoso and P. Zanca and L. Zakharov and G. Zadvitskiy and B. Zaar and R. Yi and V. Yanovskiy and H. Yang and Y. Yakovenko and Tuomas Tala and Antti Snicker and Konsta S{\"a}rkim{\"a}ki and Antti Salmi and Jari Likonen and Adam Kit and Anu Kirjasuo and Juuso Karhunen and Aaro J{\"a}rvinen and Antti Hakola and \{et al.\} and \{EUROfusion Tokamak Exploitation Team\} and \{MAST Upgrade Team\}",

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year = "2025",

doi = "10.1038/s41560-025-01824-7",

language = "English",

volume = "10",

pages = "1116--1131",

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Kool, B, Verhaegh, K, Derks, GL, Wijkamp, TA, Koenders, JTW, Lonigro, N, McArdle, G, Vincent, C, Lovell, J, Henderson, SS, Federici, F, Brida, D, Reimerdes, H, Osborne, N, van Berkel, M, Tala, T , Snicker, A , Särkimäki, K , Salmi, A , Likonen, J , Kit, A, Kirjasuo, A, Karhunen, J , Järvinen, A , Hakola, A, et al., EUROfusion Tokamak Exploitation Team & MAST Upgrade Team 2025, 'Demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors', Nature Energy, vol. 10, pp. 1116-1131. https://doi.org/10.1038/s41560-025-01824-7

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T1 - Demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors

AU - Kool, B.

AU - Verhaegh, K.

AU - Derks, G.L.

AU - Wijkamp, T.A.

AU - Koenders, J.T.W.

AU - Lonigro, N.

AU - McArdle, G.

AU - Vincent, C.

AU - Lovell, J.

AU - Henderson, S.S.

AU - Federici, F.

AU - Brida, D.

AU - Reimerdes, H.

AU - Osborne, N.

AU - van Berkel, M.

AU - Zychor, I.

AU - Zurita, M.

AU - Zuin, M.

AU - Zou, X.

AU - Zotta, V. K.

AU - Zohar, A.

AU - Zlobinski, M.

AU - Zimmermann, C. F.B.

AU - Zestanakis, P.

AU - Zerbini, M.

AU - Zebrowski, J.

AU - Zayachuk, Y.

AU - Zarzoso, D.

AU - Zanca, P.

AU - Zakharov, L.

AU - Zadvitskiy, G.

AU - Zaar, B.

AU - Yi, R.

AU - Yanovskiy, V.

AU - Yang, H.

AU - Yakovenko, Y.

AU - Tala, Tuomas

AU - Snicker, Antti

AU - Särkimäki, Konsta

AU - Salmi, Antti

AU - Likonen, Jari

AU - Kit, Adam

AU - Kirjasuo, Anu

AU - Karhunen, Juuso

AU - Järvinen, Aaro

AU - Hakola, Antti

AU - et al.

AU - EUROfusion Tokamak Exploitation Team

AU - MAST Upgrade Team

PY - 2025

Y1 - 2025

N2 - 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 cost-effective pathways towards commercial fusion energy. Alternative Divertor Configurations (ADCs) are a potential solution. In this work, we demonstrate exhaust control in ADCs, employing a novel method to diagnose the neutral gas buffer, which shields the target. Our work on the Mega Ampere Spherical Tokamak Upgrade shows that ADCs tackle key risks and uncertainties for fusion energy. Their highly reduced sensitivity to perturbations enables active exhaust control in otherwise unfeasible situations and facilitates an increased passive absorption of transients, which would otherwise damage the divertor. We observe a strong decoupling of each divertor from other reactor regions, enabling near-independent control of the divertors and core plasma. Our work showcases the real-world benefits of ADCs for effective heat load management in fusion power reactors.

AB - 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 cost-effective pathways towards commercial fusion energy. Alternative Divertor Configurations (ADCs) are a potential solution. In this work, we demonstrate exhaust control in ADCs, employing a novel method to diagnose the neutral gas buffer, which shields the target. Our work on the Mega Ampere Spherical Tokamak Upgrade shows that ADCs tackle key risks and uncertainties for fusion energy. Their highly reduced sensitivity to perturbations enables active exhaust control in otherwise unfeasible situations and facilitates an increased passive absorption of transients, which would otherwise damage the divertor. We observe a strong decoupling of each divertor from other reactor regions, enabling near-independent control of the divertors and core plasma. Our work showcases the real-world benefits of ADCs for effective heat load management in fusion power reactors.

UR - https://www.scopus.com/pages/publications/105016793617

U2 - 10.1038/s41560-025-01824-7

DO - 10.1038/s41560-025-01824-7

M3 - Article

AN - SCOPUS:105016793617

SN - 2058-7546

VL - 10

SP - 1116

EP - 1131

JO - Nature Energy

JF - Nature Energy

ER -

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

Abstract

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UN SDGs

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