Key gravity wave suspension system proves to be minimizing noise
Key gravity wave suspension system proves to be minimizing noise lead image
In order to observe ripples in space-time more than a billion light years away, gravitational wave detectors like the Laser Interferometer Gravitational-Wave Observatory (LIGO) must make measurements within one one-thousandth of the diameter of a proton. In this fine-tuned approach, even the microseismic vibrations of waves crashing on a seashore hundreds of miles away can lead to noisy data. Recent research into how seismic vibrations affect data demonstrate the effectiveness of LIGO’s suspensions.
An international team of researchers working with the LIGO facility in Livingston, Louisiana, have studied how noise in vibration-reducing mechanisms propagates toward key mirrors in the observatory. As reported in Review of Scientific Instruments, the team used actuators within the mechanisms to measure how stages of the quadruple suspension system reduced transient vibrations affecting the facility’s test masses.
Upgrades to the detectors in recent years have added more robust stages of isolation for the cavity optics to overcome seismic noise. This includes quadruple suspensions for test masses, each with a series of sensors to determine the motion of each component, and actuators to keep the mirrors carefully aligned.
Applying a force using suspension actuators produced transient low-frequency vibrations, which were measured by sensors on different stages of the suspension. While the level of precision of the sensors pales in comparison to that of the entire LIGO facility, the sensors are performing as expected, and are sufficient to show that the reduction in transient noise matches predictions.
The team’s work provides an understanding as the laser interferometers continue to see upgrades, becoming ever more sensitive as LIGO researchers continue to investigate potential noise sources.
Source: “Effects of transients in LIGO suspensions on searches for gravitational waves,” by M. Walker, T. D. Abbott, S. M. Aston, G. González, D. M. Macleod, J. McIver, B. P. Abbott, R. Abbott, C. Adams, R. X. Adhikari, S. B. Anderson, A. Ananyeva, S. Appert, K. Arai, S. W. Ballmer, D. Barker, B. Barr, L. Barsotti, J. Bartlett, I. Bartos, J. C. Batch, A. S. Bell, J. Betzwieser, G. Billingsley, J. Birch, S. Biscans, C. Biwer, C. D. Blair, R. Bork, A. F. Brooks, G. Ciani, F. Clara, S. T. Countryman, M. J. Cowart, D. C. Coyne, A. Cumming, L. Cunningham, K. Danzmann, C. F. Da Silva Costa, E. J. Daw, D. DeBra, R. T. DeRosa, R. DeSalvo, K. L. Dooley, S. Doravari, J. C. Driggers, S. E. Dwyer, A. Effler, T. Etzel, M. Evans, T. M. Evans, M. Factourovich, H. Fair, A. Fernández Galiana, R. P. Fisher, P. Fritschel, V. V. Frolov, P. Fulda, M. Fyffe, J. A. Giaime, K. D. Giardina, E. Goetz, R. Goetz, S. Gras, C. Gray, H. Grote, K. E. Gushwa, E. K. Gustafson, R. Gustafson, E. D. Hall, G. Hammond, J. Hanks, J. Hanson, T. Hardwick, G. M. Harry, M. C. Heintze, A. W. Heptonstall, J. Hough, K. Izumi, R. Jones, S. Kandhasamy, S. Karki, M. Kasprzack, S. Kaufer, K. Kawabe, N. Kijbunchoo, E. J. King, P. J. King, J. S. Kissel, W. Z. Korth, G. Kuehn, M. Landry, B. Lantz, N. A. Lockerbie, M. Lormand, A. P. Lundgren, M. MacInnis, S. Márka, Z. Márka, A. S. Markosyan, E. Maros, I. W. Martin, D. V. Martynov, K. Mason, T. J. Massinger, F. Matichard, N. Mavalvala, R. McCarthy, D. E. McClelland, S. McCormick, G. McIntyre, G. Mendell, E. L. Merilh, P. M. Meyers, J. Miller, R. Mittleman, G. Moreno, G. Mueller, A. Mullavey, J. Munch, L. K. Nuttall, J. Oberling, M. Oliver, P. Oppermann, Richard J. Oram, B. O’Reilly, D. J. Ottaway, H. Overmier, J. R. Palamos, H. R. Paris, W. Parker, A. Pele, S. Penn, M. Phelps, V. Pierro, I. Pinto, M. Principe, L. G. Prokhorov, O. Puncken, V. Quetschke, E. A. Quintero, F. J. Raab, H. Radkins, P. Raffai, S. Reid, D. H. Reitze, N. A. Robertson, J. G. Rollins, V. J. Roma, J. H. Romie, S. Rowan, K. Ryan, T. Sadecki, E. J. Sanchez, V. Sandberg, R. L. Savage, R. M. S. Schofield, D. Sellers, D. A. Shaddock, T. J. Shaffer, B. Shapiro, P. Shawhan, D. H. Shoemaker, D. Sigg, B. J. J. Slagmolen, B. Smith, J. R. Smith, B. Sorazu, A. Staley, K. A. Strain, D. B. Tanner, R. Taylor, M. Thomas, P. Thomas, K. A. Thorne, E. Thrane, C. I. Torrie, G. Traylor, D. Tuyenbayev, G. Vajente, G. Valdes, A. A. van Veggel, A. Vecchio, P. J. Veitch, K. Venkateswara, T. Vo, C. Vorvick, R. L. Ward, J. Warner, B. Weaver, R. Weiss, P. Weßels, B. Willke, C. C. Wipf, J. Worden, G. Wu, H. Yamamoto, C. C. Yancey, Hang Yu, Haocun Yu, L. Zhang, M. E. Zucker, and J. Zweizig, Review of Scientific Instruments (2017). The article can be accessed at https://doi.org/10.1063/1.5000264 .
