Francis Halzen
Name in native script: Francis Halzen
Belgian-American particle physicist, scientific founder of the IceCube Neutrino Observatory and pioneer of neutrino astronomy — 2026 Nobel laureate in Physics.
Francis Halzen was born in Belgium in 1944 and earned a physics PhD from the University of Louvain before moving to the US. He is a professor at the University of Wisconsin–Madison, where he launched AMANDA and later IceCube. His breakthrough idea was to use Antarctic glacial ice itself as a giant natural neutrino detector: astrophysical neutrinos rarely interact with matter, but each collision produces a shower of charged particles travelling faster than light in ice, emitting faint blue Cherenkov light that thousands of photodetectors buried deep in the ice can record. In 2013, after decades of development, IceCube formally detected astrophysical neutrinos at PeV energies, opening the era of neutrino astronomy. In October 2026 the Royal Swedish Academy of Sciences awarded him the Nobel Prize in Physics for these contributions.
Nobel-winning work
The 2026 Nobel Prize in Physics went to Francis Halzen "for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin". He proposed using Antarctic glacial ice as a neutrino target — the idea behind IceCube, a 1 km³ array under the South Pole ice that detects neutrinos via Cherenkov light from secondary charged particles. Since 2013 IceCube has repeatedly detected PeV astrophysical neutrinos, opening the field of neutrino astronomy.
Workplaces: University of Wisconsin–Madison, Amundsen–Scott South Pole Station
United States, Belgium