IceCube Neutrino Observatory
IceCube is a high-energy neutrino observatory, which registered in the clear ice of the South Pole since 2010 in a volume of 1 km3 of high-energy neutrinos, when they react with the elementary particles of ice. This is done by generated electrons, muons or tauons using highly sensitive optical sensors ( photomultiplier tubes ) are thereby detected. Scientists hope to gain from IceCube especially insights on what are the sources of charged cosmic rays in which the neutrinos are produced.
The principle used is already in the AMANDA telescope application and delivered there since 1997 data. On 11 May 2009, AMANDA was switched off according to plan. Following the success of the funds for the IceCube telescope were approved. IceCube was completed after nearly six years of construction and a decade of preparation on December 18, 2010. First scientific results have already been achieved with the first stages of expansion of IceCube operated in common with AMANDA. The far most important scientific result is the first observation of high-energy cosmic neutrino radiation in 2013.
IceCube has 86 wires with a total of 5160 sensors, which detect the light traces of muons, electrons and tauons, amplify, digitize and then forward to the Amundsen -Scott South Pole Station. The 677 modules of AMANDA were concomitantly used in some IceCube analyzes.
The harnesses and detectors are immersed in hot water with drilled holes, then freeze again; the sensors are placed at depths of 1450-2450 meters, where all disturbing air bubbles are ready compressed by the enormous pressure that they no longer play a role in the propagation of light.
Functioning and spectrum analysis
Best suited for a determination of direction of the neutrinos is the detection of muons. The extremely rare collision of a muon - neutrinos with a molecule causes the splitting of the nucleus and the conversion of neutrinos in a muon. The muon continues the track of the neutrino and relies a cone of blue light free, the Cherenkov radiation is called. This extremely faint light radiation is amplified by photomultiplier from Hamamatsu Photonics over 100 million times. Using the arrival times of the light at the individual sensors, the scientists calculate the direction from which came the the effect of generating neutrino.
Neutrino telescopes like IceCube can also discover supernovae or contribute to the detection of dark matter. Also directed ray bursts (so-called gamma -ray bursts ) that may emanate from black holes in the center of a spiral galaxy, for example, play a role. In this respect the system and the " trappings " is an explicit example of the rapidly emerging collaboration between high energy physics and astrophysics.
In November 2013, the IceCube Collaboration, published in the journal Science, the detection of extragalactic neutrinos. This was the first ever successful detection of neutrinos coming from distant galaxies.
Funding and partnerships
The total cost of about 270 million U.S. dollars expensive neutrino detector originate mainly from the American Science Foundation NSF. The project was co-financed by but significantly universities and institutes in Sweden, Belgium, Germany, Great Britain, Japan and the Netherlands.
The IceCube team consists of a total of about 260 scientists from 40 research institutions in eleven countries that operate and develop the detector continuously. In addition to researchers from the countries that have IceCube financed, but scientists are also from New Zealand, Australia, Canada and Switzerland participate in the operation and data analysis. From Germany, the German Electron Synchrotron DESY, the Aachen Technical University, Humboldt University, Berlin, Bochum, Bonn, TU Dortmund, Mainz, Wuppertal and TU Munich are involved.