Advanced LIGO detector performance in the fourth observing run

Capote, E.; Jia, W.; Aritomi, N.; Nakano, M.; Xu, V.; Abbott, R.; Abouelfettouh, I.; Adhikari, R. X.; Ananyeva, A.; Appert, S.; Apple, S. K.; Arai, K.; Aston, S. M.; Ball, M.; Ballmer, S. W.; Barker, D.; Barsotti, L.; Berger, B. K.; Betzwieser, J.; Bhattacharjee, D.; Billingsley, G.; Biscans, S.; Blair, C. D.; Bode, N.; Bonilla, E.; Bossilkov, V.; Branch, A.; Brooks, A. F.; Brown, D. D.; Bryant, J.; Cahillane, C.; Cao, H.; Clara, F.; Collins, J.; Compton, C. M.; Cottingham, R.; Coyne, D. C.; Crouch, R.; Csizmazia, J.; Cumming, A.; Dartez, L. P.; Davis, D.; Demos, N.; Dohmen, E.; Driggers, J. C.; Dwyer, S. E.; Effler, A.; Ejlli, A.; Etzel, T.; Evans, M.; Feicht, J.; Frey, R.; Frischhertz, W.; Fritschel, P.; Frolov, V. V.; Fuentes-Garcia, M.; Fulda, P.; Fyffe, M.; Ganapathy, D.; Gateley, B.; Gayer, T.; Giaime, J. A.; Giardina, K. D.; Glanzer, J.; Goetz, E.; Goetz, R.; Goodwin-Jones, A. W.; Gras, S.; Gray, C.; Griffith, D.; Grote, H.; Guidry, T.; Gurs, J.; Hall, E. D.; Hanks, J.; Hanson, J.; Heintze, M. C.; Helmling-Cornell, A. F.; Holland, N. A.; Hoyland, D.; Huang, H. Y.; Inoue, Y.; James, A. L.; Jamies, A.; Jennings, A.; Jones, D. H.; Kabagoz, H. B.; Karat, S.; Karki, S.; Kasprzack, M.; Kawabe, K.; Kijbunchoo, N.; King, P. J.; Kissel, J. S.; Komori, K.; Kontos, A.; Kumar, Rahul; Kuns, K.; Landry, M.; Lantz, B.; Laxen, M.; Lee, K.; Lesovsky, M.; Villarreal, F. Llamas; Lormand, M.; Loughlin, H. A.; Macas, R.; MacInnis, M.; Makarem, C. N.; Mannix, B.; Mansell, G. L.; Martin, R. M.; Mason, K.; Matichard, F.; Mavalvala, N.; Maxwell, N.; McCarrol, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McRae, T.; Mera, F.; Merilh, E. L.; Meylahn, F.; Mittleman, R.; Moraru, D.; Moreno, G.; Mullavey, A.; Nelson, T. J. N.; Neunzert, A.; Notte, J.; Oberling, J.; O'Hanlon, T.; Osthelder, C.; Ottaway, D. J.; Overmier, H.; Parker, W.; Patane, O.; Pele, A.; Pham, H.; Pirello, M.; Pullin, J.; Quetschke, V.; Ramirez, K. E.; Ransom, K.; Reyes, J.; Richardson, J. W.; Robinson, M.; Rollins, J. G.; Romel, C. L.; Romie, J. H.; Ross, M. P.; Ryan, K.; Sadecki, T.; Sanchez, A.; Sanchez, E. J.; Sanchez, L. E.; Savage, R. L.; Schaetzl, D.; Schiworski, M. G.; Schnabel, R.; Schofield, R. M. S.; Schwartz, E.; Sellers, D.; Shaffer, T.; Short, R. W.; Sigg, D.; Slagmolen, B. J. J.; Soike, C.; Soni, S.; Srivastava, V.; Sun, L.; Tanner, D. B.; Thomas, M.; Thomas, P.; Thorne, K. A.; Todd, M. R.; Torrie, C. I.; Traylor, G.; Ubhi, A. S.; Vajente, G.; Vanosky, J.; Vecchio, A.; Veitch, P. J.; Vibhute, A. M.; von Reis, E. R. G.; Warner, J.; Weaver, B.; Weiss, R.; Whittle, C.; Willke, B.; Wipf, C. C.; Wright, J. L.; Yamamoto, H.; Zhang, L.; Zucker, M. E.

doi:10.1103/physrevd.111.062002

Published March 3, 2025 | Version Published

Journal Article Open

Advanced LIGO detector performance in the fourth observing run

1. Syracuse University
2. Laser Interferometer Gravitational Wave Observatory
3. California Institute of Technology
4. Massachusetts Institute of Technology
5. University of California, Berkeley
6. University of Washington
7. University of Oregon
8. Stanford University
9. Kenyon College
10. Missouri University of Science and Technology
11. University of Western Australia
12. Max Planck Institute for Gravitational Physics
13. Leibniz University Hannover
14. University of Adelaide
15. University of Birmingham
16. University of Glasgow
17. Cardiff University
18. University of Florida
19. Louisiana State University
20. University of British Columbia
21. Universität Hamburg
22. VU Amsterdam
23. National Central University
24. Australian National University
25. University of Tokyo
26. Bard College
27. Sungkyunkwan University
28. The University of Texas Rio Grande Valley
29. University of Portsmouth
30. Montclair State University
31. University of California, Riverside

On May 24, 2023, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), joined by the Advanced Virgo and KAGRA detectors, began the fourth observing run for a two-year-long dedicated search for gravitational waves. The LIGO Hanford and Livingston detectors have achieved an unprecedented sensitivity to gravitational waves, with an angle-averaged median range to binary neutron star mergers of 152 and 160 Mpc, and duty cycles of 65.0% and 71.2%, respectively, with a coincident duty cycle of 52.6%. The maximum range achieved by the LIGO Hanford detector is 165 Mpc and the LIGO Livingston detector 177 Mpc, both achieved during the second part of the fourth observing run. For the fourth run, the quantum-limited sensitivity of the detectors was increased significantly due to the higher intracavity power from laser system upgrades and replacement of core optics, and from the addition of a 300 m filter cavity to provide the squeezed light with a frequency-dependent squeezing angle, part of the A+ upgrade program. Altogether, the A+ upgrades led to reduced detector-wide losses for the squeezed vacuum states of light which, alongside the filter cavity, enabled broadband quantum noise reduction of up to 5.2 dB at the Hanford observatory and 6.1 dB at the Livingston observatory. Improvements to sensors and actuators as well as significant controls commissioning increased low frequency sensitivity. This paper details these instrumental upgrades, analyzes the noise sources that limit detector sensitivity, and describes the commissioning challenges of the fourth observing run.

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Acknowledgement

The authors gratefully acknowledge the support of the United States National Science Foundation (NSF) for the construction and operation of the LIGO Laboratory and Advanced LIGO as well as the Science and Technology Facilities Council (STFC) of the United Kingdom, and the Max-Planck-Society (MPS) for support of the construction of Advanced LIGO. Additional support for Advanced LIGO was provided by Australian Research Council Grant No. LE210100002. The authors acknowledge the LIGO Scientific Collaboration Fellows program for additional support under Grants No. PHY-1912598 and No. PHY-2309212. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation, and operates under cooperative agreement PHY-2309200. Advanced LIGO was built under Grant No. PHY-18680823459. The A+ Upgrade to Advanced LIGO. is supported by U.S. NSF Grant No. PHY-1834382 and UK STFC Grant No. ST/S00246/1, with additional support from the Australian Research Council. This document carries LIGO Document No. P2400256.

Data Availability

The data that support the findings of this article are not publicly available, but will be made available in blocks following the LIGO Data Management Plan [115]. Some data in this paper can be made available before these dates upon reasonable request.

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Is new version of: Discussion Paper: arXiv:2411.14607 (arXiv)

Max Planck Society
Australian Research Council
LE210100002
National Science Foundation
PHY-1912598
National Science Foundation
PHY-2309212
National Science Foundation
PHY-2309200
National Science Foundation
PHY-18680823459
National Science Foundation
PHY-1834382
Science and Technology Facilities Council
ST/S00246/1
California Institute of Technology
Massachusetts Institute of Technology

Accepted: 2025-01-29

Accepted

Caltech groups: LIGO, Division of Physics, Mathematics and Astronomy (PMA)
Other Numbering System Name: LIGO Document
Other Numbering System Identifier: P2400256
Publication Status: Published

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Advanced LIGO detector performance in the fourth observing run

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Advanced LIGO detector performance in the fourth observing run

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