Monday, 9. September 2019 11 a.m.
Guest talk by: Rick Savage
Institute: LIGO Hanford Observatory
Location: Seminarraum im Einsteinbau (1.OG, Raum 201)
LIGO's direct observation of gravitational waves in September 2015 initiated the new field of gravitational wave astronomy. The 4-km-long LIGO interferometers sense relative length variations on the order of 10^-19 m. Maximizing scientific benefit requires displacement calibration accuracy of better than one percent. LIGO employs “Photon Calibrators” that rely on laser radiation pressure to induce fiducial modulated displacements of 40 kg suspended mirrors. The accuracy of these systems is directly related to the calibration of their laser power sensors.
This talk will briefly introduce gravitational waves, the LIGO laser interferometers, and the signals observed thus far. It will then focus on the LIGO Photon Calibrators and efforts, both within the gravitational wave detector community and with the National Metrology Institute community, to achieve the required overall and relative calibration accuracy for the global network of gravitational wave detectors.
