Barry Barish AIP Conference, Sydney Australia 11-July-02 LIGO Status and Plans Barry Barish AIP Conference, Sydney Australia 11-July-02

2007 11-July-02 AIP Conference

A tour of LIGO

LIGO Sites Hanford Observatory Livingston Observatory 11-July-02 AIP Conference

LIGO Livingston Observatory 11-July-02 AIP Conference

LIGO Hanford Observatory 11-July-02 AIP Conference

Detection Strategy coincidences Two Sites - Three Interferometers Single Interferometer non-gaussian level ~50/hr Hanford (Doubles) correlated rate (x1000) ~1/day Hanford + Livingston uncorrelated (x5000) <0.1/yr Data Recording (time series) gravitational wave signal (0.2 MB/sec) total data (16 MB/s) on-line filters, diagnostics, data compression off line data analysis, archive etc Signal Extraction signal from noise (vetoes, noise analysis) templates, wavelets, etc 11-July-02 AIP Conference

The Beam Tube & Enclosure

LIGO Facilities beam tube enclosure minimal enclosure reinforced concrete no services 11-July-02 AIP Conference

LIGO beam tube LIGO beam tube under construction in January 1998 65 ft spiral welded sections girth welded in portable clean room in the field 1.2 m diameter - 3mm stainless 50 km of weld NO LEAKS !! 11-July-02 AIP Conference

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 11-July-02 AIP Conference

Beam Tube bakeout I = 2000 amps for ~ 1 month no leaks !! final vacuum at level where it is not source of limiting noise (even future detectors) 11-July-02 AIP Conference

Vacuum Chambers

LIGO vacuum chambers 11-July-02 AIP Conference

Vacuum Chambers vibration isolation systems Reduce in-band seismic motion by 4 - 6 orders of magnitude Compensate for microseism at 0.15 Hz by a factor of ten Compensate (partially) for Earth tides 11-July-02 AIP Conference

Seismic Isolation

Seismic Isolation springs and masses damped spring cross section 11-July-02 AIP Conference

Seismic Isolation constrained layer damped springs 11-July-02 AIP Conference

Seismic Isolation 11-July-02 AIP Conference

Optics & Suspensions

Core Optics fused silica LIGO requirements Surface uniformity < 1 nm rms Scatter < 50 ppm Absorption < 2 ppm ROC matched < 3% Internal mode Q’s > 2 x 106 LIGO measurements central 80 mm of 4ITM06 (Hanford 4K) rms  = 0.16 nm optic far exceeds specification. Surface figure = / 6000 11-July-02 AIP Conference

Seismic Isolation suspension system suspension assembly for a core optic support structure is welded tubular stainless steel suspension wire is 0.31 mm diameter steel music wire fundamental violin mode frequency of 340 Hz 11-July-02 AIP Conference

Core Optics installation and alignment 11-July-02 AIP Conference

Laser & Mode Cleaner

LIGO laser Nd:YAG 1.064 mm Output power > 8W in TEM00 mode 11-July-02 AIP Conference

Laser stabilization IO PSL Interferometer 10-1 Hz/Hz1/2 10-4 Hz/ Hz1/2 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 IO 10-Watt Laser PSL Interferometer 15m 4 km Tidal Wideband 10-1 Hz/Hz1/2 10-4 Hz/ Hz1/2 10-7 Hz/ Hz1/2 11-July-02 AIP Conference

Prestabilized Laser frequency noise Simplification of beam path external to vacuum system eliminates peaks due to vibrations Broadband noise better than spec in 40-200 Hz region 11-July-02 AIP Conference

laboratory data vs e2e simulation Pre-stabilized Laser laboratory data vs e2e simulation 11-July-02 AIP Conference

Locking the Interferometers

Interferometer locking end test mass Requires test masses to be held in position to 10-10-10-13 meter: “Locking the interferometer” Light bounces back and forth along arms about 150 times Light is “recycled” about 50 times input test mass Laser signal 11-July-02 AIP Conference

Lock Acquisition 11-July-02 AIP Conference

watching the interferometer lock LIGO watching the interferometer lock Composite Video Y Arm Laser X Arm signal 11-July-02 AIP Conference

watching the interferometer lock LIGO watching the interferometer lock Y arm X arm 2 min Y Arm Reflected light Anti-symmetric port Laser X Arm signal 11-July-02 AIP Conference

E7 Engineering Run

LIGO Interferometers E7 sensitivities 11-July-02 AIP Conference

E7 Run Summary LIGO + GEO Interferometers 28 Dec 2001 - 14 Jan 2002 (402 hr) 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 + … 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 11-July-02 AIP Conference

detecting earthquakes 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. 11-July-02 AIP Conference

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), 11-July-02 AIP Conference

Detecting the Earth Tides Sun and Moon 11-July-02 AIP Conference

Run Plan commissioning & data taking Science 1 run: 13 TB data “Upper Limits” 29 June - 15 July (delayed until >Aug 1 because of broken suspension wire) 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 11-July-02 AIP Conference

Commissioning Status for S1 Science Run 11-July-02 AIP Conference

LHO 2 km Interferometer Status Locked in power recycled configuration recycling factor up to 25, but typically ~15 Common mode servo implemented Frequency stabilization from average arm length Establishes control system “gain hierarchy” 5 W power into mode cleaner Attenuators at photodiodes give effective input power 20 - 40 mW Tidal feedback operational Lock duration up to 15 hours DISPLACEMENT Sensitivity Summer 2001 ~ 3 x 10-16 m/Hz1/2 December 2001 (E7) ~ 5 x 10-17 m /Hz1/2 (~600 Hz) Spring 2002 ~ 2 x 10-17 m /Hz1/2 (~350 Hz) 11-July-02 AIP Conference

Interferometer sensitivity history 11-July-02 AIP Conference

LHO 4 km Interferometer status In-vacuum installation completed last summer Digital suspension controllers Greater flexibility for tuning servos to improve reliability/noise Permits frequency dependent orthogonalization of the displacement and angular control of the suspensions Will be implemented on other interferometers after tests done 1 W power into mode cleaner Attenuators at photodiodes give effective input power 20 mW Locked in power recycled configuration Recycling factor typically 40-50 Tidal feedback operational Locks up to 4 hours DISPLACEMENT Sensitivity ~2 x 10-16 m/Hz1/2 11-July-02 AIP Conference

Interferometer sensitivity history 11-July-02 AIP Conference

LLO 4 km Interferometer status Power recycled configuration 1.9 W power input laser power into mode cleaner Power recycling gain ~ 50 25-30 dB attenuation at dark port Reasonably robust lock during night Up to 4 hours 15 s – 3 min lock acquisition time Tidal feedback operational Wavefront alignment control operating on end mirrors Microseismic feedforward reduces the dynamic range required from the controller (unique to LLO at present time) PEPI reduces the seismic noise injected between 0.3 to 5 Hz at the end masses DISPLACEMENT Sensitivity ~1.5 x 10-17 m/Hz1/2 @ 400 - 600 Hz 11-July-02 AIP Conference

Interferometer sensitivity history 11-July-02 AIP Conference

Astrophysical Sources signatures and data analysis 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” 11-July-02 AIP Conference

“Chirp Signal” binary inspiral determine distance from the earth r masses of the two bodies orbital eccentricity e and orbital inclination i 11-July-02 AIP Conference

Interferometer Data 40 m prototype Real interferometer data is UGLY!!! (Gliches - known and unknown) LOCKING NORMAL RINGING ROCKING 11-July-02 AIP Conference

The Problem How much does real data degrade complicate the data analysis and degrade the sensitivity ?? Test with real data by setting an upper limit on galactic neutron star inspiral rate using 40 m data 11-July-02 AIP Conference

“Clean up” data stream Effect of removing sinusoidal artifacts using multi-taper methods Non stationary noise Non gaussian tails 11-July-02 AIP Conference

Inspiral ‘Chirp’ Signal Template Waveforms “matched filtering” 687 filters 44.8 hrs of data 39.9 hrs arms locked 25.0 hrs good data sensitivity to our galaxy h ~ 3.5 10-19 mHz-1/2 expected rate ~10-6/yr 11-July-02 AIP Conference

Optimal Signal Detection Want to “lock-on” to one of a set of known signals Requires: source modeling efficient algorithm many computers 11-July-02 AIP Conference

Detection Efficiency Simulated inspiral events provide end to end test of analysis and simulation code for reconstruction efficiency Errors in distance measurements from presence of noise are consistent with SNR fluctuations 11-July-02 AIP Conference

Results from 40m Prototype Loudest event used to set upper-limit on rate in our Galaxy: R90% < 0.5 / hour 11-July-02 AIP Conference

Setting a limit Upper limit on event rate can be determined from SNR of ‘loudest’ event Limit on rate: R < 0.5/hour with 90% CL e = 0.33 = detection efficiency An ideal detector would set a limit: R < 0.16/hour 11-July-02 AIP Conference

Astrophysical Sources signatures and data analysis 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” 11-July-02 AIP Conference

“Burst Signal” supernova n’s light gravitational waves 11-July-02 AIP Conference

Supernovae gravitational waves Non axisymmetric collapse ‘burst’ signal Rate 1/50 yr - our galaxy 3/yr - Virgo cluster 11-July-02 AIP Conference

Supernovae asymmetric collapse? pulsar proper motions Velocities - young SNR(pulsars?) > 500 km/sec Burrows et al recoil velocity of matter and neutrinos 11-July-02 AIP Conference

Supernovae signatures and sensitivity 11-July-02 AIP Conference

Astrophysical Sources signatures and data analysis 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” 11-July-02 AIP Conference

Periodic Signals spinning neutron stars Isolated neutron stars with deformed crust Newborn neutron stars with r-modes X-ray binaries may be limited by gravitational waves 11-July-02 AIP Conference

“Periodic Signals” pulsars sensitivity Pulsars in our galaxy non axisymmetric: 10-4 < e < 10-6 science: neutron star precession; interiors narrow band searches best 11-July-02 AIP Conference

Astrophysical Sources signatures and data analysis 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” 11-July-02 AIP Conference

“Stochastic Background” cosmological signals ‘Murmurs’ from the Big Bang signals from the early universe Cosmic microwave background 11-July-02 AIP Conference

Stochastic Background sensitivity Detection Cross correlate Hanford and Livingston Interferometers Good Sensitivity GW wavelength  2x detector baseline f  40 Hz Initial LIGO Sensitivity   10-5 Advanced LIGO Sensitivity   5 10-9 11-July-02 AIP Conference

Stochastic Background coherence plots LHO 2K & LHO 4K 11-July-02 AIP Conference

Stochastic Background coherence plot LHO 2K & LLO 4K 11-July-02 AIP Conference

Stochastic Background analysis in progress Analytic calculation of expected upper limits (~50 hrs): W ~2 x 105 for LLO-LHO 2k, W ~ 6 x 104 for LHO 2k-LHO 4k Coherence measurements of GW channels show little coherence for LLO-LHO 2k correlations Power line monitor coherence investigations suggest coherence should average out over course of the run Plan to investigate effect of line removal on LHO 2k-LHO 4k correlations (e.g., reduction in correlated noise, etc.) Plan to inject simulated stochastic signals into the data and extract from the noise Plan to also correlate LLO with ALLEGRO bar detector ALLEGRO was rotated into 3 different positions during E7 11-July-02 AIP Conference

Stochastic Background projected sensitivities 11-July-02 AIP Conference

LIGO conclusions 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 Significant improvements in sensitivity anticipated to begin about 2006 11-July-02 AIP Conference

Finis

Planned Detector Modifications active external seismic BSC HAM 11-July-02 AIP Conference

Advanced Detector R&D and Advanced LIGO

Advanced LIGO R&D Status Working toward construction proposal to Fall 2002 “bottoms-up” costing has nearly been completed Plan assumes construction funding available 1Q2005 some long lead funds in 1Q2004 Supports an installation start of 4Q2006 Soon ready to confront scope decisions (number of interferometers, trimming features to control costs, etc.) Advanced R&D program is proceeding well GEO and ACIGA teams forming strong international partnership 11-July-02 AIP Conference

Advanced LIGO R&D Status Interferometer Sensing & Control (ISC): GEO 10m “proof of concept” experiment: Preparation proceeding well Results available for 40m Program in early 2003 (lock acquisition experience, sensing matrix selection, etc.) 40m Lab for Precision Controls Testing: Infrastructure has been completed (i.e. PSL, vacuum controls & envelope, Data Acquisition system, etc.) Working on the installation of the 12m input MC optics and suspensions, and suspension controllers by 3Q02 Gingin facility for High Power Testing: Within the next year the LIGO Lab will deliver two characterized sapphire test masses and a prototype thermal compensation system (beam scan and/or ring heater) The facility development is advancing nicely Activities closely linked with subsystem, LASTI R&D plan 11-July-02 AIP Conference

Advanced LIGO R&D Status Seismic Isolation system (SEI): Development of pre-isolation system accelerated for use in retrofit on initial LIGO hydraulic & electro-magnet actuation variants To be tested at the LASTI facility “Technology Demonstrator” system has been fabricated a two stage, 12 degree of freedom active, stiff, isolation system being installed into the Stanford Engineering Test Facility (ETF) LASTI infrastructure has been completed (including BSC stack to support pre-isolation full scale testing for initial LIGO) 11-July-02 AIP Conference

Advanced LIGO R&D Status Suspension System (SUS): Complete fused-quartz fiber suspensions functioning in the GEO-600 interferometer Progress, in theory and in experiment, on both circular fibers (tapered) and ribbons Dynamics testing is underway on a quadruple pendulum prototype Silica-sapphire hydroxy-catalysis bonding looks feasible; silica-leadglass to be explored Significant design work underway for ‘triple’ suspensions TNI nearing final results for fused silica; sapphire mirrors ready in Fall 2002 for next phase 11-July-02 AIP Conference

Advanced LIGO R&D Status Core Optics Components (COC): New optical homogeneity measurements along the ‘a’ crystal axis are close to acceptable (13nm RMS over 80mm path length) Tests to compensate for optical inhomogeneity if required, look promising (computer controlled ‘spot’ polishing and ion beam etching) Recent sapphire annealing efforts are encouraging (reductions to 20 ppm/cm vs a requirement of 10 ppm/cm) Coatings on large optics show sub-ppm losses (SMA/Mackowski) Coating mechanical loss program in full swing; materials rather than interfaces seem to be the culprit 11-July-02 AIP Conference