LIGO Present and Future. Barry Barish Directory of the LIGO Laboratory

Transcription

1 LIGO Present and Future Barry Barish Directory of the LIGO Laboratory

2 LIGO I Schedule and Plan LIGO I has been built by LIGO Lab (Caltech & MIT) 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 LIGO I Science Run) LIGO I data run (one year integrated data at h ~ ) Begin Advanced LIGO installation 2

3 LIGO Scientific Collaboration March 02 LSC Institutional Membership 35 institutions > 350 collaborators University of Adelaide ACIGA Australian National University ACIGA California State Dominquez Hills Caltech LIGO Caltech Experimental Gravitation CEGG Caltech Theory CART University of Cardiff GEO Carleton College Cornell University University of Gainesville Glasgow University GEO University of Hannover GEO Harvard-Smithsonian India-IUCAA IAP Nizhny Novgorod Iowa State University Joint Institute of Laboratory Astrophysics LIGO Livingston LIGOLA LIGO Hanford LIGOWA Louisiana State University Louisiana Tech University MIT LIGO Max Planck (Garching) GEO Max Planck (Potsdam) GEO University of Michigan Moscow State University NAOJ - TAMA University of Oregon Pennsylvania State University Exp Pennsylvania State University Theory Southern University Stanford University University of Texas@Brownsville University of Western Australia ACIGA University of Wisconsin@Milwaukee International India, Russia, Germany, U.K, Japan and Australia. The international partners are involved in all aspects of the LIGO research program. 3

4 LIGO Sites Hanford Observatory Livingston Observatory 4

5 LIGO Livingston Observatory 5

6 LIGO Hanford Observatory 6

7 Coincidences between the LIGO Sites! Two Sites Three interferometers! Single interferometer non-gaussian level ~50/hour! Local coincidence - Hanford 2K and 4K ( ~1000) ~1/day! Hanford/Livingston coincidence (uncorrelated) <0.1/yr! GEO coincidence further reduces the false signal rate! Data (continuous time-frequency record)! Gravitational wave signal 0.2MB/sec! Total data recorded 16 MB/sec! Gravitational Wave Signal Extraction! Signal from noise (noise analysis, vetoes, coincidences, etc 7

8 LIGO Facility Noise Levels! Fundamental Noise Sources! Seismic at low frequencies! Thermal at mid frequencies! Shot at high frequencies! Facility Noise Sources (example)! Residual Gas! 10-6 torr H 2 unbaked! 10-9 torr H 2 baked 8

9 Beam Pipe and Enclosure! Minimal Enclosure (no services)! Beam Pipe! 1.2m diam; 3 mm stainless! 65 ft spiral weld sections! 50 km of weld (NO LEAKS!) 9

10 Baking out the LIGO Beam Pipe insulation ~ 2000 amps for one month Fermilab Magnet Power Supply 10

11 Vacuum Chambers and Seismic Isolation Vacuum Chambers constrained layer damped springs Vacuum Chamber Gate Valve passive isolation 11

12 LIGO I Suspension and Optics Single suspension 0.31mm music wire fused silica Surface figure = λ/ 6000 surface uniformity < 1nm rms scatter < 50 ppm absorption < 2 ppm internal Q s >

13 Commissioning the LIGO I Subsystems stablization Tidal 10-Watt Laser Wideband 15 m 4 km PSL IO Interferometer 10-1 Hz/Hz 1/ Hz/Hz 1/ Hz/Hz 1/2 Nd:Yag mm Output power >8 Watt TEM00 mode LIGO I Goal 13

14 LIGO Prestablized Laser Data vs Simulation 14

15 LIGO I Interferometer Configuration Requires test masses to be held in position to meter: Locking the interferometer end test mass Light bounces back and forth along arms about 150 times Light is recycled about 50 times input test mass Laser signal 15

16 Locking the LIGO I Interferometers One meter, about 40 inches 10, , ,000 1,000 Human Earthtides, hair, about 100 microns Wavelength Microseismic of motion, light, about 1 1 micron Atomic Precision diameter, required 10to -10 lock, meterabout meter Nuclear diameter, meter LIGO sensitivity, meter 16

17 Watching LIGO Lock Composite Video Y Arm Laser signal X Arm 17

18 Watching an Early Lock Y arm X arm 2 min Y Arm Reflected light Anti-symmetric port Laser signal X Arm 18

19 Lock Acquisition LIGO I Dynamical Control Model by Matt Evans Caltech 19

20 LIGO Engineering Run (E7) Sensitivities Final LIGO Milestone Coincidences Between the Sites in 2001 Engineering Run 28 Dec 01 to 14 Jan 02 20

21 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 %) 5X: ALLEGRO + Conclusion: Large Duty Cycle Looks Attainable 21

22 LIGO Sensitivity History Hanford 2K Livingston 4K

23 LIGO I Astrophysical Sources Search Efforts! 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 23

24 Stochastic Background Sensitivity! Detection! Cross correlate Hanford and Livingston Interferometers! Good Sensitivity! GW wavelength 2x detector baseline f 40 Hz! Initial LIGO Sensitivity Ω 10-5! Advanced LIGO Sensitivity Ω

25 Stochastic Background Coherence Plots 25

26 Stochastic Background Sensitivities 26

27 LIGO I Status and Plans! LIGO construction complete! 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; goal is to obtain and analyze one year of integrated data at h ~ by 2006! Significant improvements in sensitivity anticipated to begin about

28 Advanced LIGO Status and Plans! GEO, ACIGA and LIGO form a very strong international partnership to develop and manage Advanced LIGO! Working toward NSF construction proposal to be submitted in Fall 2002! Advanced R&D program is proceeding well! Baseline design and installation scenarios established (alternative carried)! Bottoms-up costing has nearly been completed! Plan assumes long lead funds available in 2004; major construction funds in 2005! Supports an installation by