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 cryost at 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 anten na. The expected working temperature of the antenna, transducer and in ner vibration isolation stage is about 50 mK. We implemented additiona l features to increase the long term reliability of AURIGA, particular ly in the dilution refrigerator. The design provides also for a separa te cryostat with short thermal cycle, which will house the signal ampl ification stage. This allows independent temperature control of the cr yogenic electronics and helps its optimization and maintenance.