Professor of Physics and Professor of Astronomy
3064 (office), 3061/3109 (lab) Physics Research Building
Areas of Expertise
- Experimental particle astrophysics
- Cosmic rays
- Ph.D. Physics, University of Chicago, 1986
- A.B. Chemistry, University of Chicago, 1982
Particle acceleration is ubiquitous in the Universe, and produces cosmic rays and neutrinos at extremely high energies. My group develops detectors and electronics aimed at studying the origin and composition of these energetic particles. I led the development of the surface detector electronics for the Pierre Auger Observatory, the world's largest cosmic ray detector. I am now working on experiments that exploit the emission of coherent radiofrequency Cherenkov radiation in dense media to search for neutrino-induced showers in polar ice. These include the Antarctic Impulsive Transient Antenna (ANITA) and its successor PUEO, the Askaryan Radio Array (ARA) at South Pole, and successor experiments in Greenland and Antarctica. ANITA has set limits on neutrinos from the GZK process and discovered GHz radio emission from cosmic ray air showers. I have also been taking part in the IceCube optical Cherenkov experiment at South Pole, which has observed astrophysical neutrinos in the TeV to PeV energy range. I am working with IceCube and the radio Cherenkov community to build on these discoveries and move toward a next-generation neutrino observatory at the South Pole. I am also working on the HELIX experiment to study confinement of Galactic cosmic rays by measuring the 10Be clock isotope abundance.