Study of Low Frequency Vibration Isolation System for Large Scale Gravitational Wave Detectors

Gravitational waves are distortions of spacetime which propagate through space at the speed of light. Several large-scale interferometers have been constructed around the world for the direct detection of them. The first generation detectors (TAMA, GEO, LIGO and Virgo) have performed scientific observation since 1999. They had detection probabilities of gravitational waves from binary neutron star coalescences only a few percent per year at best, and have not achieved the gravitational wave detection. Currently the second generation detectors (advanced LIGO, advanced Virgo and KAGRA) with improved sensitivities are being upgraded or constructed. They are designed to have detection probabilities of gravitational waves from binary neutron star coalescences multiple times per year, and are expected to achieve the first gravitational wave detection through years of observation. The second generation detectors also feature in expanding the detection band to lower frequency down to ∼ 10 Hz, which allows detection of gravitational waves from a greater variety of astronomical sources, such as intermediate mass black hole (IMBH) binaries and spinning pulsars with long rotation periods.