LIGO Status and Plans. Barry Barish / Gary Sanders 13-May-02

Transcription

1 LIGO Status and Plans Barry Barish / Gary Sanders 13-May-02

2 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» 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 10 3!!)» Time scale: operational by May-02 Baltimore / Koonin Briefing 2

3 Astrophysical Signatures physics 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 13-May-02 Baltimore / Koonin Briefing 3

4 Known Pulsars maximum gravitational wave signal Jones, gr-qc/ May-02 Baltimore / Koonin Briefing 4

5 Periodic Signals pulsars sensitivity! Pulsars in our galaxy» non axisymmetric: 10-4 < ε < 10-6» science: neutron star precession; interiors» narrow band searches best» all sky searches 13-May-02 Baltimore / Koonin Briefing 5

6 LIGO Plans schedule 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) LIGO I data run (one year integrated data at h ~ ) 2006 Begin Advanced LIGO installation 13-May-02 Baltimore / Koonin Briefing 6

7 The LIGO Observatories LIGO Hanford Observatory [LHO] 26 km north of Richland, WA LIGO Livingston Observatory [LLO] 42 km east of Baton Rouge, LA 13-May-02 Baltimore / Koonin Briefing 7

8 Summary integrated schedule 13-May-02 Baltimore / Koonin Briefing 8

9 LIGO costs & commitments 13-May-02 Baltimore / Koonin Briefing 9

10 LIGO contingency vs percent complete 13-May-02 Baltimore / Koonin Briefing 10

11 Staffing history 13-May-02 Baltimore / Koonin Briefing 11

12 Staffing labor distribution projections 13-May-02 Baltimore / Koonin Briefing 12

13 Major NSF Reviews Operations Renewal ! 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 May-02 Baltimore / Koonin Briefing 13

14 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= 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. 13-May-02 Baltimore / Koonin Briefing 14

15 LIGO Plans schedule 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) LIGO I data run (one year integrated data at h ~ ) 2006 Begin LIGO II installation 13-May-02 Baltimore / Koonin Briefing 15

16 Laser stabilization! Deliver pre-stabilized laser light to the 15-m mode cleaner Frequency fluctuations In-band power fluctuations Power fluctuations at 25 MHz! Provide actuator inputs for further stabilization Wideband Tidal Tidal Wideband 15m 4 km 10-Watt Laser PSL IO Interferometer 10-1 Hz/Hz 1/ Hz/ Hz 1/ Hz/ Hz 1/2 13-May-02 Baltimore / Koonin Briefing 16

17 LIGO laser! Nd:YAG! µm! Output power > 8W in TEM00 mode 13-May-02 Baltimore / Koonin Briefing 17

18 Prestabalized Laser performance! > 25,000 hours continuous operation! Frequency and lock very robust! TEM 00 power > 8 watts! Non-TEM 00 power < 10%! Improvements in optical path brought noise to better than design at low frequencies 13-May-02 Baltimore / Koonin Briefing 18

19 Lock Acquisition 13-May-02 Baltimore / Koonin Briefing 19

20 E7 Run Summary LIGO + GEO Interferometers 28 Dec 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 %) 13-May-02 Baltimore / Koonin Briefing 20

21 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 13-May-02 Baltimore / Koonin Briefing 21

22 Engineering Test Run 2 weeks Jan 02 PRELIMINARY 4 Km Hanford 4 Km Livingston 2 Km Hanford 13-May-02 Baltimore / Koonin Briefing 22

23 Strain Spectra for E7 comparison with design sensitivity LIGO I Design 13-May-02 Baltimore / Koonin Briefing 23

24 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 Hz band for four seismometer channels. We turned off lock acquisition and are waiting for the ground motion to calm down. 13-May-02 Baltimore / Koonin Briefing 24

25 17:03:03 01/02/2002 ========================================================================= Seismo-Watch Earthquake Alert Bulletin No ========================================================================= 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: E Focal depth: 33.0km Analysis Quality: A Source: National Earthquake Information Center (USGS-NEIC) Seismo-Watch, Your Source for Earthquake News and Information. Visit ========================================================================= 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), 13-May-02 Baltimore / Koonin Briefing 25 =========================================================================

26 Detecting the Earth Tides Sun and Moon 13-May-02 Baltimore / Koonin Briefing 26

27 Stochastic Background projected sensitivities evolution 13-May-02 Baltimore / Koonin Briefing 27

28 Improvements LHO 2K Jan 02 preliminary Closed feedback loop from arms to laser frequency Reallocation of gains within length control servo system 13-May-02 Baltimore / Koonin Briefing 28

29 Interferometer Sensitivities Evolution of TAMA 13-May-02 Baltimore / Koonin Briefing 29

30 Noise Level contributing components 13-May-02 Baltimore / Koonin Briefing 30

31 Run Plan commissioning & 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 January 2004» 26 weeks -- 50% of 1 yr» Target sensitivity: 5x design 13-May-02 Baltimore / Koonin Briefing 31

32 LIGO Scientific Collaboration LIGO I 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 International Members:! ACIGA (Australia)! GEO 600 (UK/Germany)! IUCAA (Pune, India) 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 13-May-02 Baltimore / Koonin Briefing 32

33 LIGO summary! 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 ~ May-02 Baltimore / Koonin Briefing 33