IceCube neutrino detector is running hot

The building that houses the IceCube servers.

USAP.gov

With the IceCube detector now in operation at the South Pole, the first results are starting to come in, and boy are they interesting. IceCube monitors a volume of one cubic kilometer of ice for muons, the byproduct of neutrinos colliding with the ice. What makes IceCube different is that it is looking especially for very high energy neutrinos. In the lower energy range, neutrinos are products of things generated very locally (in astronomical terms). Although these events are interesting, they swamp those that are produced at great distances, making it difficult to use neutrinos as a window into the Universe.

However, very distant and highly energetic events should produce neutrinos with a correspondingly high energy. If we can detect them, maybe they can tell us about those high-energy events. This idea is more than 30 years old—until now, the technology has simply not been up to the task.

IceCube consists of some 8000 photomultiplier tubes (light detectors), strung out on strings, buried under the ice of the Antarctic. Each photomultiplier tube contains its own data processing computer that provides some preliminary filtering and enables event signals to be synchronized to within 2ns. These signals are then sent to a local computing center that sits at the center of the array (yes, in Antarctica), which does more processing before sending it out to the world.