Neutrino Hunt at the South Pole

It is the southern-most large-scale experiment of the world: “IceCube” is located at the South Pole and consists of around 5000 optical sensors, held on wire ropes and inserted up to 2.5 kilometres deep into the ice of the Antarctic. The basketball-sized glass spheres register the light signals originating when neutrinos, ghost-like elementary particles, enter into one of their extremely rare reactions with normal matter. IceCube functions as a telescope and is to observe neutrinos from the far corners of space. In January 2011, the large-scale project will be completed after years of building activities. Astroparticle physicists from the DESY in Zeuthen are substantially involved.

The researchers have to bore altogether 86 holes several kilometres deep with special hot water drillers, in order to insert the wire ropes studded with sensors into the Antarctic ice. 79 holes were completed by the beginning of 2010. The physicists intend to create the remaining seven towards the end of the year, at the beginning of the Antarctic summer. “Yet with the half-finished detector we could already gather a  lot of measurement data”, says DESY physicist Dr. Christian Spiering.

So far, IceCube has registered more than ten thousand neutrinos. They come from the earth’s atmosphere, where they are created by the bombardment with cosmic radiation. In future, IceCube will also target extra-terrestrial neutrinos coming from the far outer space. “Verifying those would generate new insights as regards cosmic extreme events”, says Spiering. “We want to find out what happens in the vicinity of black holes, how a supernova explosion unfolds and how cosmic particle accelerators work, which can accelerate nuclear particles to immense energies.”