CERN - European Organization for Nuclear Research - Physics Department - NA62


The Liquid Krypton (LKr) calorimeter is a quasi-homogeneous electromagnetic calorimeter which ensures a very good intrinsic energy resolution for the experiment. It is key for vetoing photons from Kaon decays, with the requirement that the system have a photon detection inefficiency lower that 10-5

The LKr was used by NA48, and has been adapted for use by NA62. The LKr will veto γ with 10-5 inefficiency above 5 GeV, degrading gradually to 10-4 between 1 and 5 GeV. Some specifications for the LKr Calorimeter follow:

  • 10 m3 liquid Krypton calorimeter, 1.25 m deep (27X0)
  • 13284 2x2 cm2 cells, projecting geometry
  • Signal is formed by the collection of electrons ionized by the passage of a particle in the Krypton (˜2.5 µA/GeV)
  • Preamplifiers inside the LKr tank
  • Calibration system mounted on the LKr tank