Nikhef is the national institute for subatomic physics in the Netherlands. At Nikhef, approximately 250 physicists and 80 technical staff work together in an open and international scientific environment. Together they perform theoretical and experimental research in particle and astroparticle physics.
KM3NeT is a next-generation neutrino telescope taking shape on the floor of the Mediterranean Sea. Its primary scientific goals are to discover and study high-energy astrophysical neutrinos and their sources with the ARCA detector, and to investigate neutrino oscillations—including the determination of the neutrino mass ordering—with the ORCA detector. Both detectors also record enormous numbers of atmospheric muons from cosmic-ray air showers, and these muons carry information about particle interactions at energies far beyond the reach of any accelerator on Earth. In this project you will turn that signal into cosmic-ray physics: measuring the muon content of air showers, confronting high-energy hadronic-interaction models and helping to solve the long-standing “muon puzzle”. You will carry out your research in the KM3NeT group at Nikhef, which initiated and coordinates the cosmic-ray activities within the international KM3NeT Collaboration, and you will work in a friendly, supportive and international team.
As a PhD candidate you will develop new ways to extract cosmic-ray physics from KM3NeT data. You will design and characterise reconstruction methods—both machine-learning-based and traditional—for the bundles of muons that reach the detectors, and apply them to data and simulations to constrain cosmic-ray composition and hadronic-interaction models. We support you with a rich international collaboration, extensive computing resources and close day-to-day supervision within the group.
Your tasks and responsibilities include developing reconstruction algorithms for the muon bundles recorded by KM3NeT; extracting air-shower observables such as muon multiplicity, lateral separation and energy; using these observables to constrain cosmic-ray composition and high-energy hadronic-interaction models, including the atmospheric dependence of the muon flux; publishing your results in peer-reviewed journals and presenting them at international conferences; contributing to the work of the KM3NeT Collaboration; and contributing to teaching at the University of Amsterdam, for example by assisting in bachelor’s or master’s courses.
What we ask of you
You have a Master’s degree or equivalent in physics, completed by the start of the appointment; a strong interest in astroparticle and cosmic-ray physics; good programming skills; the ability and enthusiasm to work in a large international collaboration while advancing your own research; and a good command of spoken and written English. Experience with data analysis in astroparticle, particle or cosmic-ray physics is an advantage. Familiarity with machine learning may be useful, but is not expected.
We offer a temporary contract for 38 hours per week for a total duration of four years. The initial contract will be for 18 months and, after a satisfactory evaluation, will be extended to the full four-year period. The gross monthly salary, based on 38 hours per week, ranges from €3,059 to €3,881 (Scale P). This does not include 8% holiday allowance and an 8.3% year-end allowance. The UFO profile for a PhD candidate applies.
You will be employed by the University of Amsterdam and carry out your research in the KM3NeT group at Nikhef. The preferred starting date will be agreed with the successful candidate, but will be before December 2026. The appointment is intended to lead to a dissertation (PhD thesis). We will draw up an educational plan that includes attendance at courses and national and international meetings. We also expect you to assist in teaching bachelor’s and master’s students at the University of Amsterdam.
The Collective Labour Agreement of Dutch Universities applies.
You will work in this team
The Faculty of Science of the University of Amsterdam has a student body of around 8,000 and approximately 1,800 staff working in education, research and support services. Researchers and students at the Faculty of Science are fascinated by every aspect of how the world works, from elementary particles and the birth of the Universe to the functioning of the brain.
The Institute of Physics (IoP) of the University of Amsterdam is located at Amsterdam Science Park. As part of the Faculty of Science, the IoP is housed in a modern building with excellent laboratories and technical facilities. Together with several national research institutes and its partners at Vrije Universiteit Amsterdam, it forms part of a physics centre of strong international standing.
The Institute for High-Energy Physics (IHEF) is part of the IoP and carries out experimental and phenomenological research in particle and astroparticle physics. Its experimental groups—active in experiments including ATLAS, LHCb and KM3NeT—are fully embedded within Nikhef, the Dutch national institute for subatomic physics, at the same Amsterdam Science Park location. This PhD position is funded through an NWO grant and is embedded in the IHEF KM3NeT group.
Nikhef is a partnership between six major Dutch universities and NWO-I, the Institutes Organisation of the Dutch Research Council (NWO). Among the research collaborations in which Nikhef participates are ALICE, ATLAS and LHCb at CERN, the KM3NeT neutrino telescope in the Mediterranean Sea, the Virgo gravitational-wave detector, XENONnT, the Pierre Auger Observatory and the eEDM research programme. Nikhef also has scientific groups in theory, physics data processing and detector R&D, and excellently equipped technical departments in mechanics, electronics and computing.
The research is carried out in the KM3NeT group at Nikhef, which covers the full chain from detector construction and calibration to reconstruction and physics analysis. The group contributes to KM3NeT’s core neutrino programme: the search for high-energy astrophysical neutrinos and their sources with ARCA, and precision studies of neutrino oscillations and the neutrino mass ordering with ORCA. It also initiated and coordinates the cosmic-ray physics activities within the international KM3NeT Collaboration, using the atmospheric muons recorded by KM3NeT to study air showers, hadronic interactions and the cosmic-ray flux—the research of which you will be part.
Your application and contact
If the profile fits you and you are interested in the position, we look forward to receiving your application through the Nikhef application portal, see the button below. Applications will be accepted until and including August 31 2026. For further information, please contact Dr. Ronald Bruijn at [email protected].
Your application should include a detailed curriculum vitae, including the start and finish months—not only the years—of your education and work experience; a motivation letter; a list of publications, if applicable; and the names and email addresses of at least two referees who can provide letters of recommendation.
The University of Amsterdam and Nikhef attach great importance to an inclusive working environment and to the contribution of women and other under-represented groups in research and education. We particularly encourage candidates from these groups to apply. We value diversity and encourage applicants from all backgrounds to apply, even if they do not meet every requirement.
A knowledge-security check can form part of the selection procedure. Only complete applications received within the response period through the Nikhef application portal will be considered.
