Bolometric direct dark matter search at the University of Tokyo

A direct dark matter search experiment is now under preparation at the University of Tokyo. An array of LiF bolometers with a total mass of roughly one kilogram is to be used aiming at a direct detection of spin-dependently interacting supersymmetric neutralinos. A dedicated low-radioactivity dilution refrigerator for the bolometer has been constructed along with a small on-line helium requefier to help the detector operation in the underground laboratory where liquid helium supply is not always available. A long term test operation of a bolometer at the University of Tokyo proved the stability of the detector for more than 45 days. The detector will be installed in the Nokogiri-yama underground laboratory of the Institute for Cosmic Ray Research of the University of Tokyo. The laboratory is 200 m w.e. deep and located about 60 km to the south of Tokyo.