Thermal Noise in Interferometric Gravitational-Wave Detectors

verfasst von

S. Traeger, O. Jennrich, B. Willke, K. Danzmann

Abstract

The sensitivity of the interferometric gravitational-wave detectors currently being built will be limited over a significant part of the frequency range by the thermal noise of the suspended test masses. To minimize the thermal noise in the bandwith of interest, very high mechanical quality factors are required for the test masses itself as well as for the pendulum suspension. Very low losses for the pendulum mode have been reported for monolithic fused silica suspensions. We built monolithic suspensions with emphasis on a high mechanical quality factor for the internal modes of the substrate. The vibrational mode of the substrate was excited using an electrostatic drive and was monitored interferometrically. The decay time τ of the amplitude of the free oscillation was measured the mechanical quality factor was calculated from the relation, Q = πf₀τ, where f_o is the frequency of the mode. We measured the decay time of the lowest frequency mode for various lengths of the suspension to identify possible coupling to resonances in the suspension libre. We will show that by using proper fusing techniques a quality factor of at least 5×10⁶ (as assumed in [1]) is achievable for internal modes of the substrate in such a system. This indicates that monolithic test mass suspensions can be used to improve the sensitivity of advanced interferometric gravitational-wave detectors.

Organisationseinheit(en)

Institut für Atom- und Molekülphysik (AMP)

Typ

Paper

Seiten

244

Anzahl der Seiten

1

Publikationsdatum

1996

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie

Elektronische Version(en)

https://doi.org/10.1109/EQEC.1996.561947 (Zugang: Geschlossen)