Speaker: Dr. James Madsen, Department of Physics, University of Wisconsin–River Falls
Title: “Transforming the South Pole Ice into the World’s Biggest and Strangest Observatory”
Date: May 1, 2014 (Thursday)
Time: 10:00 a.m.
Place: Seminar Room, CNL C-310
Physics World’s 2013 Breakthrough of the Year award went to the IceCube Neutrino Observatory at the South Pole for making the first observations of high-energy cosmic neutrinos. The idea to explore the Universe by detecting neutrinos goes back more than five decades. Even early promoters knew that mapping the cosmos with high-energy neutrinos would require a detector of unprecedented size—a cubic kilometer of pristine transparent material. The initial idea was to deploy a grid of light sensors in water, and smaller neutrino telescopes are currently operating in the Mediterranean Sea, and in Lake Baikal in Russia. But so far, only the aptly named international IceCube Collaboration has constructed a cubic-kilometer-scale detector, and in the last year they isolated convincing evidence for high-energy neutrinos produced in outer space.
The IceCube Neutrino Observatory, the result of decades of design and seven seasons of construction in the South Pole ice sheet, is an incredible example of creativity, perseverance, and a bit of luck. The IceCube Collaboration delivered a detector on time, on budget, and exceeding design performance specifications. Dedicated teams worked hard to deploy over 5000 light sensors to depths between 1450 and 2450 meters below the surface. With some equally amazing ingenuity, scientists were able to find about one dozen cosmic high-energy neutrinos per year out of the roughly one hundred billion events recorded annually. This talk will provide an introduction to the neutrino, describe how we detect it and what it tells us, and give an idea of what it is like to live and work at the South Pole.