Sensitivity of the Rome Gravitational Wave Experiment with the Explorer Cryogenic Resonant Antenna Operating at 2 K

We report on the results obtained with a cryogenic gravitational wave antenna equipped with a d.c. SQUID, operating at 2 K. During a period of a few days in April 1989 the measured noise temperature (for short bursts of gravitational waves) was Teff 7 mK corresponding to a sensitivity of hc 710-19. This result allows to improve the previously published upper limits for the rate of gravitational wave bursts.