IceTop on Top of IceCube


      IceTop is a km2 array of particle detectors that is installed at the South Pole, right above the IceCube neutrino telescope. It is used to detect extended particle showers induced in our atmosphere by high-energy cosmic rays.

      Its spacing (80 stations = 160 Cherenkov ice tanks, 125 m mean distance) allows the observation of cosmic rays with energies between 1014 eV and 1017 eV. In this regime, the energy spectrum is expected to include 2 kinks: The first, already observed by most experiments, is at the energy where presumably light cosmic rays (protons) start to be able to escape the magnetic fields of our galaxy and the observed fluxes thus decrease faster above than below ("knee"). A second "knee" is expected but yet unobserved for heavier particles like iron nuclei. Using IceCube as a high-energy neutrino detector and the CORSIKA air shower simulation package, IceTop can identify the masses of primary cosmic ray particles and unfold the energy spectra for different primaries.

      Being a part of IceCube, the main goals of IceTop sum up to be the following:

      • Using the InIce-part of IceCube to scan the potential second-knee-regime in the Cosmic Ray Energy Spectrum for different primaries
      • calibrating IceCube using coincident muon bundles and comparing reconstruction results
      • enhance the noise detection of IceCube by providing a veto on muons generated by air showers above the telescope

      Installation status of IceTop
       

      Stations deployed

      Tanks deployed

      % of total array

      2006

      16

      32

      20

      2007

      26

      52

      33

      2008

      40

      80

      50

      2009

      59

      118

      74

      2010

      73

      146

      91

      2011

      81

      162

      100