Photo of: Francis Halzen
Francis Halzen is the principal investigator of IceCube, Hilldale and Gregory Breit Professor at UW–Madison, and a theoretician studying problems that span the particle physics, astrophysics and cosmology communities. In 1987, Halzen started working on the AMANDA experiment, a first-generation neutrino telescope at the South Pole that represented a proof of concept for the IceCube Neutrino Observatory. Halzen also serves on advisory committees for the SNO, Telescope Array, and the Auger upgrade experiments, the Max Planck Institutes in Heidelberg and Munich, the ICRR of the University of Tokyo, the US Particle Physics Prioritization Panel, and the ApPEC particle astrophysics advisory panel in Europe.
Photo of: Kael Hanson
Kael Hanson is the director of WIPAC, the IceCube Director of Operations, as well as a professor of physics at the University of Wisconsin–Madison. Kael has played a major role in the development and construction of IceCube, first managing the development of the IceCube optical modules and later the IceCube data acquisition system. He comes back to WIPAC after spending six years as a faculty member in the Department of Physics at the Université Libre de Bruxelles in Brussels, Belgium where he led the particle astrophysics group. His principal research interests include high-energy neutrino astrophysics and related instrumentation, design of digital logic systems in particular, precision time applications, and firmware development. In addition to IceCube, he is also a member of the ARA Collaboration.
Photo of: Albrecht Karle
Albrecht Karle is the IceCube Associate Director for Science and Instrumentation, the Principal Investigator for ARA, and a professor of physics at the University of Wisconsin–Madison. His research is focused on high-energy neutrino astronomy and astrophysics. With IceCube, he focuses on research with neutrinos of all flavors at energies above 30 TeV. He is also exploring new ways to detect ultra-high-energy neutrinos using radio detectors. Karle currently mentors several graduate students and postdocs in addition to serving as the department chair.
Photo of: Justin Vandenbroucke
Justin Vandenbroucke is an assistant professor in the Department of Physics at the University of Wisconsin–Madison, with a joint appointment in the Astronomy Department. His work at WIPAC includes research in gamma-ray and neutrino astronomy and cosmic rays. Vandenbroucke is the Principal Investigator for the Distributed Electronic Cosmic-Ray Observatory, DECO, a citizen science project that allows users around the world to detect cosmic rays and other energetic particles with their cell phones and tablets. In addition to his work with DECO, Vandenbroucke is a member of the IceCube, Cherenkov Telescope Array, and Fermi collaborations.
Photo of: Stefan Westerhoff
Stefan Westerhoff is a professor of physics at the University of Wisconsin–Madison. He is a member of the IceCube and the HAWC collaborations. Primary research interests include the search for sources of high-energy cosmic rays and the study of the sky in gamma rays at TeV energies. Recent research includes the study of anisotropy in the arrival direction of cosmic rays with both IceCube and HAWC.

Faculty Profiles

WIPAC faculty and students are involved in IceCube, the Askaryan Radio Array (ARA), the High-Altitude Water Cherenkov (HAWC) experiment, Cherenkov Telescope Array (CTA), Big Data, and DM-Ice.


In keeping with our vision, we encourage and support visits from researchers who have interests, or who wish to develop interests, in several of our research areas.


The postdoctoral fellowship program was created to honor the late John Bahcall, a prominent physicist and a founding member of the IceCube experiment.  In 2015 the Balzan Fellowship was created after Francis Halzen was awarded the Balzan Prize.