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LIGO Status and Plans Barry Barish / Gary Sanders 13-May-02. LIGO overall strategy. Strategy presented to NSB by Thorne / Barish in 1994 Search with a first generation interferometer where detection of gravitational waves are ‘plausible’ LIGO I uses demonstrated technologies
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LIGOoverall strategy • Strategy presented to NSB by Thorne / Barish in 1994 • Search with a first generation interferometer where detection of gravitational waves are ‘plausible’ • LIGO I uses demonstrated technologies • Design sensitivity h ~ 10-21 • Plan is to interleave interferometer studies and improvements with incrementally improving data runs • Search Goal: one year of integrated data at ~ design sensitivity • Advanced LIGO – detection “likely” • Do enabling R&D and design in parallel with LIGO I • Incremental upgrades to laser, suspensions, optics, test masses • Sensitivity: ~ 15x improvement (rate improves by 103 !!) • Time scale: operational by 2008 Baltimore / Koonin Briefing
Astrophysical Signaturesphysics goals • Compact binary inspiral: “chirps” • NS-NS waveforms are well described • BH-BH need better waveforms • search technique: matched templates • Supernovae / GRBs: “bursts” • burst signals in coincidence with signals in electromagnetic radiation • prompt alarm (~ one hour) with neutrino detectors • Pulsars in our galaxy: “periodic” • search for observed neutron stars (frequency, doppler shift) • all sky search (computing challenge) • r-modes • Cosmological Signals “stochastic background” Baltimore / Koonin Briefing
Known Pulsarsmaximum gravitational wave signal Jones, gr-qc/0111007 Baltimore / Koonin Briefing
“Periodic Signals”pulsars sensitivity • Pulsars in our galaxy • non axisymmetric: • 10-4 < e < 10-6 • science: neutron star precession; interiors • narrow band searches best • all sky searches Baltimore / Koonin Briefing
LIGO Plansschedule 1996 Construction Underway (mostly civil) 1997 Facility Construction (vacuum system) 1998 Interferometer Construction (complete facilities) 1999 Construction Complete (interferometers in vacuum) 2000 Detector Installation (commissioning subsystems) 2001 Commission Interferometers (first coincidences) 2002 Sensitivity studies (initiate short data taking runs) 2003+ LIGO I data run (one year integrated data at h ~ 10-21) 2006 Begin Advanced LIGO installation Baltimore / Koonin Briefing
The LIGO Observatories LIGO Hanford Observatory [LHO] 26 km north of Richland, WA LIGO Livingston Observatory [LLO] 42 km east of Baton Rouge, LA Baltimore / Koonin Briefing
Summary integrated schedule Baltimore / Koonin Briefing
LIGOcosts & commitments Baltimore / Koonin Briefing
LIGOcontingency vs percent complete Baltimore / Koonin Briefing
Staffinghistory Baltimore / Koonin Briefing
Staffinglabor distribution projections Baltimore / Koonin Briefing
Major NSF ReviewsOperations Renewal - 2001 • Review of Operations Proposal • Review of Advanced R&D Proposal • Requested $175M for 5 years of operations • Outstanding reviews – • “The Review Panel was extremely impressed with all aspects of the LIGO Program and feels that it should receive the highest possible rating” • “The Review Panel recommends that the NSF, even in the eventuality of overall fiscal pressures, support the LIGO program at the requested level.” • Funding approved by NSB (Aug 01) at $160M • Annual LIGO Review • Concentrated on computing facilities • Next review – Fall 02 Baltimore / Koonin Briefing
NSF Review Panel LIGO Goals and Plans “The two goals of the program for the next five-year period were described to the Panel. The first goal is the operation of the LIGO I interferometers to search for gravitational waves with the strain sensitivity of h=10-21. This sensitivity is sufficient to make plausible, but not to guarantee, significant discoveries. The second goal is to pursue the R&D necessary for the design and construction of the Advanced LIGO interferometers with a 15-fold sensitivity improvement. Since the number of detectable sources is expected to scale as the cube of the sensitivity, Advanced LIGO is crucial in realizing the scientific goals of the program. The Review Panel felt that both of these goals are of paramount importance, and that the balance between the resources planned by LIGO on these two efforts is about right.” Baltimore / Koonin Briefing
LIGO Plansschedule 1996 Construction Underway (mostly civil) 1997 Facility Construction (vacuum system) 1998 Interferometer Construction (complete facilities) 1999 Construction Complete (interferometers in vacuum) 2000 Detector Installation (commissioning subsystems) 2001 Commission Interferometers (first coincidences) 2002 Sensitivity studies (initiate short data taking runs) 2003+ LIGO I data run (one year integrated data at h ~ 10-21) 2006 Begin LIGO II installation Baltimore / Koonin Briefing
Deliver pre-stabilized laser light to the 15-m mode cleaner Frequency fluctuations In-band power fluctuations Power fluctuations at 25 MHz Tidal Wideband 4 km 15m 10-Watt Laser Interferometer PSL IO Laserstabilization • Provide actuator inputs for further stabilization • Wideband • Tidal 10-1 Hz/Hz1/2 10-4 Hz/ Hz1/2 10-7 Hz/ Hz1/2 Baltimore / Koonin Briefing
LIGO laser • Nd:YAG • 1.064 mm • Output power > 8W in TEM00 mode Baltimore / Koonin Briefing
Prestabalized Laserperformance • > 25,000 hours continuous operation • Frequency and lock very robust • TEM00 power > 8 watts • Non-TEM00 power < 10% • Improvements in optical path brought noise to better than design at low frequencies Baltimore / Koonin Briefing
Lock Acquisition Baltimore / Koonin Briefing
E7 Run SummaryLIGO + GEO Interferometers 28 Dec 2001 - 14 Jan 2002 (402 hr) Singles data All segments Segments >15min L1 locked 284hrs (71%) 249hrs (62%) L1 clean 265hrs (61%) 231hrs (53%) L1 longest clean segment: 3:58 H1 locked 294hrs (72%) 231hrs (57%) H1 clean 267hrs (62%) 206hrs (48%) H1 longest clean segment: 4:04 H2 locked 214hrs (53%) 157hrs (39%) H2 clean 162hrs (38%) 125hrs (28%) H2 longest clean segment: 7:24 Coincidence Data All segments Segments >15min 2X: H2, L1 locked 160hrs (39%) 99hrs (24%) clean 113hrs (26%) 70hrs (16%) H2,L1 longest clean segment: 1:50 3X : L1+H1+ H2 locked 140hrs (35%) 72hrs (18%) clean 93hrs (21%) 46hrs (11%) L1+H1+ H2 : longest clean segment: 1:18 4X: L1+H1+ H2 +GEO: 77 hrs (23 %)26.1 hrs (7.81 %) Baltimore / Koonin Briefing
LIGO I the noise floor • Interferometry is limited by three fundamental noise sources • seismic noise at the lowest frequencies • thermal noise at intermediate frequencies • shot noise at high frequencies • Many other noise sources lurk underneath and must be controlled as the instrument is improved Baltimore / Koonin Briefing
Engineering Test Run2 weeks – Jan 02 PRELIMINARY 4 Km Hanford 4 Km Livingston 2 Km Hanford Baltimore / Koonin Briefing
Strain Spectra for E7comparison with design sensitivity LIGO I Design Baltimore / Koonin Briefing
Engineering Run detecting earthquakes From electronic logbook 2-Jan-02 An earthquake occurred, starting at UTC 17:38. The plot shows the band limited rms output in counts over the 0.1- 0.3Hz band for four seismometer channels. We turned off lock acquisition and are waiting for the ground motion to calm down. Baltimore / Koonin Briefing
17:03:03 01/02/2002 ========================================================================= Seismo-Watch Earthquake Alert Bulletin No. 02-64441 ========================================================================= Preliminary data indicates a significant earthquake has occurred: Regional Location: VANUATU ISLANDS Magnitude: 7.3M Greenwich Mean Date: 2002/01/02 Greenwich Mean Time: 17:22:50 Latitude: 17.78S Longitude: 167.83E Focal depth: 33.0km Analysis Quality: A Source: National Earthquake Information Center (USGS-NEIC) Seismo-Watch, Your Source for Earthquake News and Information. Visit http://www.seismo-watch.com ========================================================================= All data are preliminary and subject to change. Analysis Quality: A (good), B (fair), C (poor), D (bad) Magnitude: Ml (local or Richter magnitude), Lg (mblg), Md (duration), ========================================================================= Baltimore / Koonin Briefing
Detecting the Earth Tides Sun and Moon Baltimore / Koonin Briefing
Stochastic Background projected sensitivities evolution Baltimore / Koonin Briefing
Improvements LHO 2K – Jan 02preliminary • Closed feedback loop from arms to laser frequency • Reallocation of gains within length control servo system Baltimore / Koonin Briefing
Interferometer Sensitivities Evolution of TAMA Baltimore / Koonin Briefing
Noise Levelcontributing components Baltimore / Koonin Briefing
Run Plancommissioning & data taking • • Science 1 run: 13 TB data “Upper Limits” • 29 June - 15 July • 2.5 weeks - comparable to E7 • Target sensitivity: 200x design • • Science 2 run: 44 TB data “Upper Limits” • 22 November - 6 January 2003 • 8 weeks -- 15% of 1 yr • Target sensitivity: 20x design • • Science 3 run: 142 TB data “Search Run” • 1 July 2003 -- 1January 2004 • 26 weeks -- 50% of 1 yr • Target sensitivity: 5x design Baltimore / Koonin Briefing
LIGO Scientific CollaborationLIGO I International Members: • ACIGA (Australia) • GEO 600 (UK/Germany) • IUCAA (Pune, India) US Universities: • Caltech LIGO/CaRT/CEGG/CACR • Carleton • Cornell • Cal State University Dominguez Hills • Florida • Louisiana State • Louisiana Tech • Michigan • MIT LIGO • Oregon • Penn State • Southern • Syracuse • Texas-Brownsville • Wisconsin-Milwaukee US Agencies & Institutions • FNAL (DOE) • Goddard-GGWAG (NASA) • Harvard-Smithsonian International partners (have MOUs with LIGO Laboratory): • TAMA (Japan) • Virgo (France/Italy) 21 Institutions, 26 Groups, 281 Members Baltimore / Koonin Briefing
LIGOsummary • LIGO construction completed in 2000 • LIGO commissioning and testing ‘on track’ • Engineering test runs underway, during period when emphasis is on commissioning, detector sensitivity and reliability. • Short upper limit data runs interleaved • First Science Search Run : first search run will begin during 2003 • Significant improvements in sensitivity ~ 2008 Baltimore / Koonin Briefing