Sensitivity enhancement of the gravitational detector OGRAN

Abstract

The gravitational wave antenna OGRAN is installed in the underground laboratory of the Baksan Neutrino Observatory. At the present time, it has a limited sensitivity sufficient only to detect gravitational radiation from sources situated at a distance of about 100 kpc. The calculations presented in this paper demonstrate the increase in the sensitivity by two orders of magnitude with cooling of the acoustical resonator of the antenna to the liquid-nitrogen temperature. The possibility of using the same optical detection scheme as the one under room temperature is discussed. The revised construction of the cryogenic version of the OGRAN antenna is considered. The results of experiments carried out with the pilot model of cryogenic antenna are presented.