Personal Chair
Telephone: (01792) 602652
Room: Office - 503
Fifth Floor
Vivian Building
Singleton Campus

At Swansea University since 2005, Professor Madsen is an experimental physicist who specializes in work on fundamental physics with antimatter. He is co-founder and group leader in the ALPHA collaboration that was the first group to trap antihydrogen and observe the first quantum transitions in it and is pursuing precision comparisons with hydrogen. He has been actively involved in antihydrogen research since 2001, playing a substantial role in the ATHENA team that first formed low energy antihydrogen in 2002. He has a research group at CERN. His group plays a leading role in the ALPHA experiment in both physics and hardware and software design, and led the effort to implement several key techniques leading to the first antihydrogen trapping. It has furthermore conceptualised, designed and built significant parts of the ALPHA apparatus. For this work he has been awarded a Royal Society Senior Leverhulme Fellowship in 2010, and the 2011 James Dawson award for Excellence in Plasma Physics Research.

Areas of Expertise

  • Antihydrogen
  • Atomic Physics
  • Laser Cooling
  • Plasma Physics
  • Fundamental Physics
  • Spectroscopy
  • Non-neutral plasmas


  1. et. al. Observation of the 1S–2P Lyman-α transition in antihydrogen. Nature 561(7722), 211-215.
  2. et. al. Characterization of the 1S–2S transition in antihydrogen. Nature 557(7703), 71-75.
  3. & Corrigendum: Aspects of 1S–2S spectroscopy of trapped antihydrogen atoms (2017 J. Phys. B: At. Mol. Opt. Phys. Biofabrication 50 184002). Journal of Physics B: Atomic, Molecular and Optical Physics 51(9), 099501
  4. Antiproton physics in the ELENA era. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376(2116), 20170278
  5. et. al. Enhanced Control and Reproducibility of Non-Neutral Plasmas. Physical Review Letters 120(2)

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  • PH-129 Laboratory Physics I

    Laboratory Physics I

  • PH-333 Atomic Physics and Quantum Optics II

    This module covers the basics of modern topics in atomic physics and quantum optics.


  • Using Be+ ions for magnetometry in the ALPHA-g experiment. (current)

    Student name:
    Other supervisor: Prof Stefan Eriksson
  • Using sympathetically laser cooled positrons for improved antihydrogen trapping in the ALPHA-2 apparatus. (current)

    Student name:
    Other supervisor: Prof Stefan Eriksson
  • A precision study of antimatter properties (current)

    Student name:
    Other supervisor: Prof Stefan Eriksson
  • '''Improving Antihydrogen Trapping Using Beryllium-Cooled Positrons''' (awarded 2019)

    Student name:
    Other supervisor: Prof Michael Charlton
  • ''Laser-ablated Beryllium Ions for Cold Antihydrogen in ALPHA'' (awarded 2017)

    Student name:
    Other supervisor: Prof Michael Charlton
    Other supervisor: Prof Dirk Van Der Werf

Research Groups

  • Experimental Physics Research Group

    A major focus of our research is low-energy positron and positronium physics, with particular application to the creation of ultra-low energy antihydrogen. This work is a key element of the ALPHA experiment based at the Antiproton Decelerator (AD) at CERN.