Vertical and Horizontal Seismic Isolation Performance of the Advanced Virgo External Injection Bench Seismic Attenuation System

• DOI: 10.1016/j.phpro.2014.12.064
• Publication Date: 2015-03-24T00:02:37Z
• Authors: M.R. Blom; M.G. Beker; A. Bertolini; J.F.J. van den Brand; H.J. Bulten; M. Doets; E. Hennes; F.A. Mul; D.S. Rabeling; A. Schimmel
• Keywords: passive filter; 03 medical and health sciences; 0302 clinical medicine; seismic isolation; transfer function; Physics and Astronomy(all); Advanced Virgo

AbstractDuring the combined commissioning and science run of Virgo in 2010, an extensive noise study revealed that vibrations of some of the injection/detection optics on the external injection bench (EIB) made a significant contribution to the interferometer's noise budget. Several resonances were identified between 10 and 100Hz of the EIB support structure and between 200 and 300Hz of the optics mounts. These resonances introduced a significant amount of beam jitter that would limit the sensitivity of Advanced Virgo. This beam jitter needed to be reduced for Advanced Virgo to reach its full potential. To eliminate this noise source we developed a seismic attenuation system to isolate the EIB from ground vibrations: EIB-SAS. It employs vertical and horizontal passive seismic filters based on negative stiffness technology to attenuate seismic noise by 40dB above 10Hz. The isolation capabilities of the system have been characterized up to 400Hz with the aid of a custom designed piezoelectric actuated shaking platform. The results of the vertical and horizontal transfer function measurements are presented.