Professor Brian Foster OBE, FRS: Publications

Status of and upgrade concepts for HALHF: the hybrid, asymmetric, linear Higgs factory

Journal of Physics: Conference Series IOP Publishing 3124:1 (2025) 012001

Authors:

CA Lindstrøm, R D’Arcy, B Foster

Abstract:

This contribution outlines the HALHF concept, which combines the high gradients achievable in plasma-wakefield acceleration with conventional radio-frequency acceleration. In HALHF, beam-driven plasma-wakefield cells are used to accelerate electrons to high energy. Because plasma-based acceleration of positrons is problematic, conventional RF acceleration is used but to much lower energy. The HALHF concept utilises not only asymmetric energies but also asymmetric bunch charges and asymmetric transverse emittances, leading to comparable luminosity to conventional facilities but much lower capital cost. Possible upgrades to the HALHF facility are discussed, in particular to the tt− threshold and to 550 GeV, where the Higgs self-coupling and tt−H coupling can be measured. Other upgrades include the provision of two interaction points, to implement a γ.γ collider of two possible types and finally a symmetric high-energy collider if the problem of plasma-based positron acceleration can be solved.

Proceedings of the Erice workshop: A new baseline for the hybrid, asymmetric, linear Higgs factory HALHF

Physics Open Elsevier 23 (2025) 100261

Authors:

Brian Foster, Erik Adli, Timothy L Barklow, Mikael Berggren, Stewart Boogert, Jian Bin Ben Chen, Richard D’Arcy, Pierre Drobniak, Sinead Farrington, Spencer Gessner, Mark J Hogan, Daniel Kalvik, Antoine Laudrain, Carl A Lindstrøm, Benno List, Jenny List, Xueying Lu, Gudrid Moortgat Pick, Kristjan Põder, Andrei Seryi, Kyrre Sjobak, Maxence Thévenet, Nicholas J Walker, Jonathan Wood

The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA

European Physical Journal C Springer Nature 84:12 (2024) 1334

Authors:

I Abt, R Aggarwal, V Aushev, O Behnke, A Bertolin, I Bloch, I Brock, NH Brook, R Brugnera, A Bruni, PJ Bussey, A Caldwell, CD Catterall, J Chwastowski, J Ciborowski, R Ciesielski, AM Cooper-Sarkar, M Corradi, RK Dementiev, S Dusini, J Ferrando, B Foster, E Gallo, D Gangadharan, A Garfagnini, A Geiser, G Grzelak, C Gwenlan, D Hochman, NZ Jomhari, I Kadenko, U Karshon, P Kaur, R Klanner, U Klein, IA Korzhavina, N Kovalchuk, M Kuze, BB Levchenko, A Levy, B Löhr, E Lohrmann, A Longhin, F Lorkowski, E Lunghi, I Makarenko, J Malka, S Masciocchi, K Nagano, JD Nam, Yu Onishchuk, E Paul, I Pidhurskyi, A Polini, M Przybycień, A Quintero, M Ruspa, U Schneekloth, T Schörner-Sadenius, I Selyuzhenkov, M Shchedrolosiev, LM Shcheglova, N Sherrill, IO Skillicorn, W Słomiński, A Solano, L Stanco, N Stefaniuk, B Surrow, K Tokushuku, O Turkot, T Tymieniecka, A Verbytskyi, WAT Wan Abdullah, K Wichmann, M Wing, S Yamada, Y Yamazaki, AF Żarnecki, O Zenaiev

Energy depletion and re-acceleration of driver electrons in a plasma-wakefield accelerator

Physical Review Research American Physical Society (APS) 6:4 (2024) 043090

Authors:

F Peña, CA Lindstrøm, J Beinortaitė, J Björklund Svensson, L Boulton, S Diederichs, B Foster, JM Garland, P González Caminal, G Loisch, S Schröder, M Thévenet, S Wesch, JC Wood, J Osterhoff, R D'Arcy

Emittance preservation in a plasma-wakefield accelerator

Nature Communications Nature Research 15:1 (2024) 6097

Authors:

CA Lindstrøm, J Beinortaitė, J Björklund Svensson, L Boulton, J Chappell, S Diederichs, B Foster, JM Garland, P González Caminal, G Loisch, F Peña, S Schröder, M Thévenet, S Wesch, M Wing, JC Wood, R D’Arcy, J Osterhoff

Abstract:

Radio-frequency particle accelerators are engines of discovery, powering high-energy physics and photon science, but are also large and expensive due to their limited accelerating fields. Plasma-wakefield accelerators (PWFAs) provide orders-of-magnitude stronger fields in the charge-density wave behind a particle bunch travelling in a plasma, promising particle accelerators of greatly reduced size and cost. However, PWFAs can easily degrade the beam quality of the bunches they accelerate. Emittance, which determines how tightly beams can be focused, is a critical beam quality in for instance colliders and free-electron lasers, but is particularly prone to degradation. We demonstrate, for the first time, emittance preservation in a high-gradient and high-efficiency PWFA while simultaneously preserving charge and energy spread. This establishes that PWFAs can accelerate without degradation—an essential step toward energy boosters in photon science and multistage facilities for compact high-energy particle colliders.

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