A new method for the absolute amplitude calibration of GEO 600

Leong, J. R. et al. (2012) A new method for the absolute amplitude calibration of GEO 600. Classical and Quantum Gravity, 29(6), 065001. (doi: 10.1088/0264-9381/29/6/065001)

Abstract

This work provides a new method for the absolute amplitude calibration of the GEO 600 interferometric gravitational wave detector. It is motivated by ongoing data analysis efforts carried out by the LIGO Scientific and Virgo Collaborations. Previously, arm length difference measurements of GEO 600 have been calibrated against the length of the first mode cleaner. Here, we re-evaluate this process, providing new measurements, and add a much simpler and more elegant method which calibrates against the laser wavelength. Since our calibration measurements involve injections of signals at least five orders of magnitude larger than possible gravitational wave signals, we also carry out a linearity check of the electrostatic drive (ESD) actuators used to make the injections. We find that these actuators exhibit no more than a 0.3% deviation from linearity over nearly six orders of magnitude. The new absolute amplitude calibration method that uses the laser wavelength as a length standard is shown here to be superior to the old one. Using this method, we show that the ESD gain over a two-year period varies by less than 4%.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hild, Professor Stefan and Strain, Professor Kenneth
• Authors: Leong, J. R., Hewitson, M., Lück, H., Grote, H., Hild, S., Affeldt, C., Degallaix, J., Freise, A., Prijatelj, M., Strain, K., Wittel, H., Willke, B., and Danzmann, K.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Research Centre: College of Science and Engineering > School of Physics and Astronomy > Institute for Gravitational Research
• Journal Name: Classical and Quantum Gravity
• Publisher: Institute of Physics
• ISSN: 0264-9381
• ISSN (Online): 1361-6382