Quadruple suspension design for Advanced LIGO
Creators
- Robertson, N. A.1, 2
- Cagnoli, G.1
- Crooks, D. R. M.1
- Elliffe, E.1
- Faller, J. E.3
- Fritschel, P.4
- Goβler, S.5
- Grant, A.1
- Heptonstall, A.1
- Hough, J.1
- Lück, H.5
- Mittleman, R.4
- Perreur-Lloyd, M.1
- Plissi, M. V.1
- Rowan, S.1, 2
- Shoemaker, D. H.4
- Sneddon, P. H.1
- Strain, K. A.1
- Torrie, C. I.1, 6
- Ward, H.1
- Willems, P.6
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1.
University of Glasgow
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2.
Stanford University
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3.
Joint Institute for Laboratory Astrophysics
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4.
Massachusetts Institute of Technology
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5.
Leibniz University Hannover
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6.
California Institute of Technology
Abstract
In this paper, we describe the conceptual design for the suspension system for the test masses for Advanced LIGO, the planned upgrade to LIGO, the US laser interferometric gravitational-wave observatory. The design is based on the triple pendulum design developed for GEO 600—the German/UK interferometric gravitational wave detector. The GEO design incorporates fused silica fibres of circular cross-section attached to the fused silica mirror (test mass) in the lowest pendulum stage, in order to minimize the thermal noise from the pendulum modes. The damping of the low-frequency modes of the triple pendulum is achieved by using co-located sensors and actuators at the highest mass of the triple pendulum. Another feature of the design is that global control forces acting on the mirrors, used to maintain the output of the interferometer on a dark fringe, are applied via a triple reaction pendulum, so that these forces can be implemented via a seismically isolated platform. These techniques have been extended to meet the more stringent noise levels planned for in Advanced LIGO. In particular, the Advanced LIGO baseline design requires a quadruple pendulum with a final stage consisting of a 40 kg sapphire mirror, suspended on fused silica ribbons or fibres. The design is chosen to aim to reach a target noise contribution from the suspension corresponding to a displacement sensitivity of 10^(−19) m Hz^(−1/2) at 10 Hz at each of the test masses.
Additional Information
© 2002 IOP Publishing Ltd. Received 10 May 2002. Published 15 July 2002. The authors would like to thank their colleagues in the GEO collaboration for their interest and help in this work. We also acknowledge with thanks members of the LIGO Scientific Collaboration (LSC) at Caltech, MIT and Stanford who have contributed, in particular Mark Barton at Caltech. The Glasgow group acknowledges the financial support of the University of Glasgow. GEO acknowledges the financial support of the Particle Physics and Astronomy Research Council (PPARC), the Bundesministerium für Bildung und Forschung (BMBF) and the state of Lower Saxony. The LIGO Laboratory thanks the National Science Foundation for its support through the cooperative agreement PHY-9210038 and the award PHY-9801158.Additional details
Identifiers
- Eprint ID
- 43304
- Resolver ID
- CaltechAUTHORS:20140110-085940181
Funding
- University of Glasgow
- Particle Physics and Astronomy Research Council (PPARC)
- Bundesministerium für Bildung und Forschung (BMBF)
- State of Lower Saxony
- NSF Cooperative Agreement
- PHY-9210038
- NSF Cooperative Agreement
- PHY-9801158
Dates
- Created
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2014-01-10Created from EPrint's datestamp field
- Updated
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2022-07-12Created from EPrint's last_modified field