2690974 20210715030742.0 oai:cds.cern.ch:2690974 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN DOI bibmatch 10.1088/1361-6382/ab4974 arXiv oai:arXiv.org:1908.11174 oai:inspirehep.net:1751759 https://inspirehep.net/api/oai2d Inspire 2021-06-29T10:36:19Z 2021-07-14T19:21:24Z marcxml true Inspire 1751759 arXiv arXiv:1908.11174 astro-ph.IM eng Cirone, A. ORCID:0000-0003-4299-8609 alessio.cirone@ge.infn.it Genoa U. INFN, Genoa INFN, Sezione di Genova, I-16146 Genova, Italy Dipartimento di Fisica, Università degli Studi di Genova, I-16146 Genova, Italy arXiv Investigation of magnetic noise in Advanced Virgo 2019-10-18 2019-08-29 14 p IOP The advanced Virgo (AdV) sensitivity might be influenced by the effects of environmental noise, in particular magnetic noise (MN). In order to show the impact on the gravitational-wave strain signal h(t) and on the AdV sensitivity, we must understand the coupling between the environmental magnetic activity and the strain. The relationship between the environmental noise—measured by a physical environment monitor (PEM)—and h(t) is investigated using injection studies, where an intentional stimulus is introduced and the responses of both PEM sensors and the instrument are analyzed. We also present the most outstanding measurements and results obtained from both the characterization and the mitigation studies of the environmental MN. Results show that MN does not affect AdV sensitivity up to 100 Mpc in BNS range. arXiv The Advanced Virgo (AdV) sensitivity might be influenced by the effects of environmental noise, in particular magnetic noise (MN). In order to show the impact on the gravitational-wave strain signal h(t) and on the AdV sensitivity, we must understand the coupling between the environmental magnetic activity and the strain. The relationship between the environmental noise - measured by a physical environment monitor (PEM) - and h(t) is investigated using injection studies, where an intentional stimulus is introduced and the responses of both PEM sensors and the instrument are analyzed. We also present the most outstanding measurements and results obtained from both the characterization and the mitigation studies of the environmental MN. Results show that MN does not affect AdV sensitivity up to $\approx 100$ Mpc in BNS range. preprint arXiv nonexclusive-distrib 1.0 http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Publication © 2019 IOP Publishing Ltd arXiv physics.ins-det SzGeCERN Detectors and Experimental Techniques arXiv gr-qc SzGeCERN General Relativity and Cosmology arXiv astro-ph.IM SzGeCERN Astrophysics and Astronomy CERN ARTICLE Fiori, I. EGO, Pisa European Gravitational Observatory (EGO), I-56021 Cascina, Pisa, Italy Paoletti, F. ORCID:0000-0001-8898-1963 INFN, Pisa INFN, Sezione di Pisa, I-56127 Pisa, Italy Perez, M.M. Barcelona, IFAE IFAE, Barcelona Institute of Science and Technology, Barcelona, and ICREA, Spain Rodríguez, A.R. CERN Erice, Majorana Ctr. IFAE, Barcelona Institute of Science and Technology, Barcelona, and ICREA, Spain Swinkels, B.L. ORCID:0000-0002-3066-3601 NIKHEF, Amsterdam Nikhef, Science Park 105, 1098 XG Amsterdam, The Netherlands Vazquez, A.M. Mexico U. IFAE, Barcelona Institute of Science and Technology, Barcelona, and ICREA, Spain Gemme, G. ORCID:0000-0002-1127-7406 Enrico Fermi Ctr., Rome Genoa U. INFN, Genoa INFN, Sezione di Genova, I-16146 Genova, Italy Chincarini, A. ORCID:0000-0003-4094-9942 INFN, Genoa INFN, Sezione di Genova, I-16146 Genova, Italy 225004 22 Class. Quantum Gravity 36 2019 1519781 1295269 http://cds.cern.ch/record/2690974/files/1908.11174.pdf Fulltext 1519782 170037 http://cds.cern.ch/record/2690974/files/figure8a.png 00010 Magnetic noise projection with coherence. a) Maximum coherence at each frequency between the strain channel and the 3 magnetic probes in the "Central Building" (blue line); the dashed red line indicates the statistical significance level of the coherence, calculated according to the 95$\%$ confidence level of the coherence distribution between randomly resampled data (orange line). b) Related magnetic noise projection (blue for statistically reliable bins, grey for coherence below significance level), compared to the most recent one obtained by the far-field injections (red diamonds) and the Advanced Virgo sensitivity (orange line). 1519783 48859 http://cds.cern.ch/record/2690974/files/figure10b.png 00014 "Finite Element Analysis" of two possible magnetic field shielding solutions: a) the Helmholtz coils and a spherical shell (different shapes and sizes). b) Longitudinal studies (along z) of the normalized reduction of the magnetic field. c) Orthogonal studies (along y) within a height range of [-1,7] m, along the "Tower" axis. d) Frequency evolution of the normalized field at the Test Mass location. 1519784 41473 http://cds.cern.ch/record/2690974/files/figure10c.png 00015 "Finite Element Analysis" of two possible magnetic field shielding solutions: a) the Helmholtz coils and a spherical shell (different shapes and sizes). b) Longitudinal studies (along z) of the normalized reduction of the magnetic field. c) Orthogonal studies (along y) within a height range of [-1,7] m, along the "Tower" axis. d) Frequency evolution of the normalized field at the Test Mass location. 1519785 42589 http://cds.cern.ch/record/2690974/files/figure10d.png 00016 "Finite Element Analysis" of two possible magnetic field shielding solutions: a) the Helmholtz coils and a spherical shell (different shapes and sizes). b) Longitudinal studies (along z) of the normalized reduction of the magnetic field. c) Orthogonal studies (along y) within a height range of [-1,7] m, along the "Tower" axis. d) Frequency evolution of the normalized field at the Test Mass location. 1519786 81262 http://cds.cern.ch/record/2690974/files/figure3b.png 00004 Frequency evolution of the West-End Tower (WET) shielding power: a) The 3 "injection coil - external magnetic probe" configurations for their positioning inside the experimental area: coil at 7.3 m, probe near the WET (config. 1); coil at 10.3 m, probe near the WET (config. 2); coil at 6.8 m, specular probe (config. 3). b) The measurement results, along with the fits to a first order lower pass filter model of Butterworth type. 1519787 107914 http://cds.cern.ch/record/2690974/files/figure10a.png 00013 "Finite Element Analysis" of two possible magnetic field shielding solutions: a) the Helmholtz coils and a spherical shell (different shapes and sizes). b) Longitudinal studies (along z) of the normalized reduction of the magnetic field. c) Orthogonal studies (along y) within a height range of [-1,7] m, along the "Tower" axis. d) Frequency evolution of the normalized field at the Test Mass location. 1519788 89286 http://cds.cern.ch/record/2690974/files/figure6b.png 00008 114.8 Hz line injection at "Central Building". It is readily visible by the 3 single-axis magnetic probes (a) and the interferometer (b), where the blue peak stands out against the reference orange curve. 1519789 101745 http://cds.cern.ch/record/2690974/files/figure6a.png 00007 114.8 Hz line injection at "Central Building". It is readily visible by the 3 single-axis magnetic probes (a) and the interferometer (b), where the blue peak stands out against the reference orange curve. 1519790 152648 http://cds.cern.ch/record/2690974/files/figure8b.png 00011 Magnetic noise projection with coherence. a) Maximum coherence at each frequency between the strain channel and the 3 magnetic probes in the "Central Building" (blue line); the dashed red line indicates the statistical significance level of the coherence, calculated according to the 95$\%$ confidence level of the coherence distribution between randomly resampled data (orange line). b) Related magnetic noise projection (blue for statistically reliable bins, grey for coherence below significance level), compared to the most recent one obtained by the far-field injections (red diamonds) and the Advanced Virgo sensitivity (orange line). 1519791 59651 http://cds.cern.ch/record/2690974/files/figure7.png 00009 Magnetic coupling measurement. The orange diamond means that the corresponding injected line is detected in the strain channel, while the green star is only an upper limit, due to bad coherence between the injected field and the strain output. The fit to the coupling function is also included. 1519792 98577 http://cds.cern.ch/record/2690974/files/figure5.png 00006 From left to right the "West-End, North-End and Central Buildings" floor plans. The thunderbolt and the blue cylinder correspond respectively to the coil and the probe locations inside the three facilities; the red spots identifies the four TMs and the red lines follow the main laser path. 1519793 123568 http://cds.cern.ch/record/2690974/files/figure4.png 00005 Comparison between three different magnetic noise levels, found near a localized noisy source, before (orange) and after its removal (green) and in correspondence of a particularly low-noise location (blue), inside the "North-End Building". 1519794 103592 http://cds.cern.ch/record/2690974/files/figure2.png 00002 Typical magnetic noise spectra detected at "Central Building" by the 3 permanent single-axis magnetometers used to monitor the magnetic activity in the experimental area. Periodic features and broader structures in the spectrum are easily identifiable as known sources. N, W and V stand respectively for North-South, West-East and Vertical directions. 1519795 121251 http://cds.cern.ch/record/2690974/files/figure3a.png 00003 Frequency evolution of the West-End Tower (WET) shielding power: a) The 3 "injection coil - external magnetic probe" configurations for their positioning inside the experimental area: coil at 7.3 m, probe near the WET (config. 1); coil at 10.3 m, probe near the WET (config. 2); coil at 6.8 m, specular probe (config. 3). b) The measurement results, along with the fits to a first order lower pass filter model of Butterworth type. 1519796 330507 http://cds.cern.ch/record/2690974/files/figure1b.png 00001 a) Top-view drawing of the "North-End Building" experimental area and the main instrumentation. TCS, HVAC and NET stand respectively for "Thermal Compensation System", "Heating, Ventilation and Air Conditioning" and "North-End Tower". b) 3D CAD picture of the relevant infrastructure, which mainly consists of the vacuum-tight enclosure of the interferometer components. 1519797 225414 http://cds.cern.ch/record/2690974/files/figure1a.png 00000 a) Top-view drawing of the "North-End Building" experimental area and the main instrumentation. TCS, HVAC and NET stand respectively for "Thermal Compensation System", "Heating, Ventilation and Air Conditioning" and "North-End Tower". b) 3D CAD picture of the relevant infrastructure, which mainly consists of the vacuum-tight enclosure of the interferometer components. 1519798 276669 http://cds.cern.ch/record/2690974/files/figure9.png 00012 Magnetic noise budget. The relevant Advanced Virgo and Advanced Virgo+ present and future sensitivity outcomes are shown as reference. The grey band represents the "Finite Element" simulation uncertainty among all the investigated electrical configurations of the payload, which is the mechanical assembly that suspend the test masses. Diamonds represent the far-field magnetic noise injections, performed 2 years apart. 1519781 2847349 http://cds.cern.ch/record/2690974/files/1908.11174.pdf?subformat=pdfa pdfa Preprint 1519781 7821 http://cds.cern.ch/record/2690974/files/1908.11174.gif?subformat=icon icon Preprint 1519781 85246 http://cds.cern.ch/record/2690974/files/1908.11174.jpg?subformat=icon-700 icon-700 Preprint 1519781 9471 http://cds.cern.ch/record/2690974/files/1908.11174.jpg?subformat=icon-180 icon-180 Preprint 13 ARTICLE