Performance of the KAGRA detector during the first joint observation with GEO 600 (O3GK)

Abstract KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan. In April 2020, an astrophysics observation was performed KAGRA detector in combination with GEO 600 detector; this operation called O3GK. The optical configuration O3GK based on a power-recycled Fabry–Pérot–Michelson interferometer; all mirrors were set room temperature. duty factor of approximately 53%, and displacement sensitivity 1 × 10?18 ${\rm m}/\sqrt{\rm {Hz}}$ 250 Hz. binary-neutron-star (BNS) inspiral range about 0.6 Mpc. contributions various noise sources to investigated understand how could be improved; study “noise budget”. According our budget, measured approximated by adding up effect each noise. dominated from sensors used for local controls vibration isolation systems, acoustic noise, shot laser frequency Further, other that did not limit investigated. This paper provides detailed account O3GK, including interferometer configuration, status, budget. addition, strategies future improvements, such as hardware upgrades, are discussed.