The Ultracryogenic Gravitational-Wave Antenna Auriga

AURIGA is a resonant gravitational wave detector under development at the INFN laboratories of Legnaro, Italy. Its main liquid Helium cryostat houses vibration isolation stages, the dilution refrigerator, the 2.3 tons cylindrical antenna and the resonant displacement transducer, in a design derived from NAUTILUS, the other INFN ultracryogenic antenna. The expected working temperature of the antenna, transducer and inner vibration isolation stage is about 50 mK. We implemented additional features to increase the long term reliability of AURIGA, particularly in the dilution refrigerator. The design provides also for a separate cryostat with short thermal cycle, which will house the signal amplification stage. This allows independent temperature control of the cryogenic electronics and helps its optimization and maintenance.