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John Felde

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John Felde

I am a postdoc at the University of Maryland working on the IceCube Neutrino Observatory, a huge (cubic kilometer) neutrino detector at the south pole. I joined the Maryland particle astrophysics group in September of 2013 after receiving my Ph.D. from the University of California, Davis. As a graduate student I worked with the Double Chooz collaboration studying the oscillation behavior of neutrinos at a French nuclear power reactor. Although both experiments detect and study the same kind of subatomic particle, the energy range of interest to the two are vastly different. Some of the most energetic neutrinos detected by IceCube thus far have about a billion times more energy than the neutrinos typically produced in a nuclear reactor. One of the most fun and interesting aspects of neutrino physics is this vast energy range available to study.

With IceCube, I have become primarily focused on adapting the experiments existing data processing schemes to allow for faster identification of interesting neutrino events. The faster we know about an interesting IceCube event, the faster we can alert other ground and space based observatories to the location of a possibly interesting astrophysical object. A primary candidate for such searches are Gamma Ray Bursts which are seen most often by satellite observatories and have historically been considered as possible high energy neutrino sources. So far, however, no confirmation of such neutrino production has been observed by IceCube.

At the other end of the IceCube neutrino energy spectrum, which is still fairly high by neutrino standards, a growing contingency studies the oscillation behavior of neutrinos produced in the upper atmosphere during the interaction of cosmic rays with the air itself. These neutrinos are fairly abundant, have a wide energy range, and come to IceCube from every direction. One weird aspect about neutrinos is their ability to “oscillate” which means change flavors between three types, electron type, muon type, and tau type. This phenomena, having roots in quantum mechanics, has been well studied and verified since the 1990’s, but IceCube’s contribution to the field is unique in that we study this behavior at the highest energies.

I was born and raised in Lodi, California, and currently live in the U St. neighborhood of Washington, DC. When I’m not researching neutrinos I can most likely be found on the soccer field or exploring the sights of the DC area.