IceCube neutrino observatory nears completion

"Almost a century after their discovery, we do not know from where the most energetic particles to hit the Earth originate and how they acquire their incredible energies," says Halzen, a professor of physics at the University of Wisconsin in Madison.

After light, neutrinos, which are created in the decay of radioactive particles, are the most abundant particles in the universe. High-energy neutrinos are formed in the universe's most violent events, like exploding stars and gamma ray bursts. Because the neutrino has no charge, essentially no mass, and only interacts weakly with matter, trillions of neutrinos pass through our bodies each day, without effect. On extremely rare occasions, a neutrino will strike the nucleus of an atom, creating a particle, called a muon, and blue light that can be detected with optical sensors. The trick is spying those collisions—and, in particular, the collisions of high-energy neutrinos. IceCube does it by sheer virtue of its size.

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IceCube scientists deploy a calibration light source, called the Standard Candle in one of the 2.5 km deep holes. Each of the 86 holes contains a string of 60 Digital Optical Modules (DOMs) that detect the blue light from neutrino events in the deep, clear ice. Credit: J. Haugen

"IceCube has been totally optimized for size in order to be sensitive to the very small neutrino fluxes that may reveal the sources of cosmic rays and the particle nature of dark matter," Halzen says.

More information: The article, "IceCube: An instrument for neutrino astronomy" by Francis Halzen and Spencer R. Klein appears in the journal Review of Scientific Instruments. See: http://rsi.aip.org … 8/p081101_s1

Provided by American Institute of Physics