In-situ measurement of the luminescence of IceCube ice

The IceCube neutrino observatory uses 1 km${}^3$ of the clear, natural ice near the geographic South Pole as an optical detection medium. When charged particles, such as neutrino secondaries, pass through the ice, Cherenkov light is emitted. The light is then recorded by embedded optical modules. However new kind of signatures, produced by exotic particles, could be detected by using light emission from luminescence. It is induced by highly ionizing particles passing through matter causing the excitation of surrounding atoms and molecules which then emit photons as they return to ground state. This process is highly dependent on the ice structure, impurities, pressure and temperature. Therefore a logging devices was build in order to measure these ice properties in-situ. For the measurements in the recent Antarctic summer season, a 1.7 km deep and 12.5 cm wide hole is used which was recently drilled near the IceCube site. The small diameter of the hole presents a challenge for the construction of the experiment and the design of the read-out electronics inside the pressure vessels. The details of the experiment as well as available measurement results will be presented.