LIGOas a
Large Science Project
Barry Barish
Ph237b
April 23, 2002
24-Apr-02 Physics 237b 2
Experimental Research
! Traditional Mode – Single Investigator» Program built around a laboratory with some equipment» Experiment built to attack particular problem» Support from private funds and/or grants» Typical support ~$150K/year» NSF, DoE, NASA
! Larger Projects : Which ones, how implemented, etc» Astronomy (private, NSF, …)» Space science (NASA)» Particle physics (DoE, NSF)» LIGO (NSF, but …)
24-Apr-02 Physics 237b 3
Experimental Research! Small Science
» Grants or private funding for the research (& infrastructure)» No direct accountability» Peer review for renewal or new grants» This system is flexible and creates experiment driven by science
and ideas
! Large Science» Large special funding required for equipment» Large National Labs (Fermilab, JPL, etc)» Direct accountability» Peer review for science + management, resources, etc» Strategic planning, high level direction, etc determine science
program
24-Apr-02 Physics 237b 4
Experimental Research! Research vs Project for Large Science
» How to create an effective research environment for large science» The system should be flexible and create experiment driven by
science and ideas» Different models
– NASA – science teams separate from project team, open data– DoE – umbrella grants, internal guidelines and reviews, collaborations, ..– Private – Keck– LIGO – NSF funded - designed to evolve into standard peer review system
! Strategic Planning» NSF top down from high level planning committees» Astronomy from Decadal Review by NAS panel» Particle Physics from National Laboratories + Road Map» LIGO – New endeavor in a new experimental field (Thorne, Drever,
Weiss, Vogt, …)
HEP Long Range Planning
A Long Range Plan for
U.S. High Energy Physics
Jon Bagger & Barry BarishBriefing for Ray Orbach, Office of Science
12-March-02
HEPAP Subpanelon
Long Range Planning
12-March-02 Summary -- Long Range Plan for HEP 2
The Goal of our SubpanelTo create a vision for the field for the next 20 years
The questions we posed for ourselves• What is our role in society and education?• What is high energy physics?• What are our goals and the paths to accomplish them?• How have we been doing?• What do we expect in the near term?• What opportunities do we identify for the longer term?• How do the U.S. and global programs interact?• What are the essential elements of a realistic program aimed
at our goals?• How can we set priorities and make the best choices?• How do we prepare for the far future?
12-March-02 Summary -- Long Range Plan for HEP 3
Developing a Long Range Strategy for HEPFrontier Pathway
Scenic and Historic BywayA “roadmap” is an extended look at the future of a chosen field of inquiry composed from the collective knowledge and imagination of the brightest drivers ofchange in that field.
R. GalvinMotorola
12-March-02 Summary -- Long Range Plan for HEP 4
SLAC
Anti-Matter Asymmetry
High Energy PhysicsRecent Accomplishments
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234B0tags
246B0tags
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��
-5 50
Dt (psec)
Top Quark EventFermilab
Neutrino Mass
Non-accelerator
12-March-02 Summary -- Long Range Plan for HEP 5
The Particle Physics RoadmapNear-Term Program
SLAC BaBar Fermilab Run 2
Precision Measurements
Next 5 Years ~ 500 fb-1 Pursuit of the Higgs
FermilabMINOS
Neutrino OscillationParameters
CDF
MINOS
12-March-02 Summary -- Long Range Plan for HEP 6
Matter, Energy, Space and Time
From each of these goals flows a diverse research program that will be carried out in partnership with colleagues across the globe.
Paths to the Goals of Particle Physics
12-March-02 Summary -- Long Range Plan for HEP 7
The Particle Physics Roadmap• We have many tools at our disposal from forefront
accelerators to satellites in space to experiments deep underground.
AcceleratorLHC Magnet
Space
Our science requires forefront accelerators at the energy and luminosity frontiers. It also requires innovative experiments in space, underground, and away from accelerators.
The Soudan MineMINOS
12-March-02 Summary -- Long Range Plan for HEP 8
CERN LHC
The Particle Physics Roadmap
The Energy Frontier
• Higgs• Supersymmetry• Extra Dimensions• New Phenomena
CERN LHC: The Next Big Step for HEP
Accelerator, Atlas, CMS
12-March-02 Summary -- Long Range Plan for HEP 9
CDF & DØH1 & Zeus
LHCENERGY FRONTIER LHC Upgrades
VLHCLinear Collider
CLICMuon Collider
NuMI/MINOSLEPTON FLAVOR PHYSICS Neutrino Superbeam
Neutrino Factory
BaBar & BELLEBTeV
QUARK FLAVOR PHYSICS CESR-cRSVPCKM
Super B Factory
UNIFICATION SCALE PHYSICS Proton DecayNUSL
COSMOLOGY SNAP
PARTICLE ASTROPHYSICS IceCubeGLAST
2000 20202005 20152010
Not all projects illustrated on the roadmap can be pursued.
The Particle Physics RoadmapLong Range Opportunities
12-March-02 Summary -- Long Range Plan for HEP 11
ROADMAP
0
200
400
600
800
1000
1200
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
YEAR
M$
NEW INITIATIVESLC OPERATIONLC OFFLHC LUM UPGRDLATTICE COMP.HI INT NEUTRINOSNAPCESR CRSVPICE CUBENUMI/MINOSCDMSSDSSVERITASPie rre Auge rGLAST LHC BASE-LABFNAL+SLAC
Scenario with off-shore linear collider
12-March-02 Summary -- Long Range Plan for HEP 12
ROADMAP
0
200
400
600
800
1000
1200
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
YEAR
M$
NEW INITIATIVESLC OPERATIONLC ONLHC LUM UPGRDLATTICE COMP.HI INT NEUTRINOSNAPCESR CRSVPICE CUBENUMI/MINOSCDMSSDSSVERITASPie rre Auge rGLAST LHC BASE-LABFNAL+SLAC
Scenario with on-shore linear collider
24-Apr-02 Physics 237b 6
LIGO Project! Organized like typical construction project (1994-2000)
» Vertical organization – every task has task manager, budget, deliverables, direct line of reporting
» Integration is the hard part» Project guided by scientists
! Evolution to Operating Research Environment (2000 - )» Flat organization – separate groups by task operating like
small laboratories (40m, TNI, Advanced R&D, data analysis, commissioning)
» New projects (Adv LIGO) done as project task within this structure
» Broader community – LSC and open data access
24-Apr-02 Physics 237b 7
Summary integrated schedule
24-Apr-02 Physics 237b 8
LIGOfacilities milestones
Milestone Description PMPProjection/
Actual PMPProjection/
Actual
Initiate Site Development Mar-94 Mar-94 Aug-95 Jun-95Beam Tube Final Design Review Apr-94 Apr-94 Apr-94 Apr-94Select A&E Contractor Nov-94 Nov-94 Nov-94 Nov-94Complete Beam Tube Qualification Test Feb-95 Apr-95 Feb-95 Apr-95Select Vacuum Equipment Contractor Mar-95 Jul-95 Mar-95 Jul-95Complete Performance Measurement Baseline Apr-95 Apr-95 Apr-95 Apr-95Initiate Beam Tube Fabrication Oct-95 Dec-95 Oct-95 Dec-95Initiate Slab Construction Oct-95 Feb-96 Jan-97 Jan-97Initiate Building Construction Jun-96 Jul-96 Jan-97 Jan-97Joint Occupancy Sep-97 Oct-97 Mar-98 Feb-98Accept Tubes and Covers Mar-98 Mar-98 Mar-99 Oct-98Beneficial Occupancy Mar-98 Mar-98 Sep-98 Dec-98Accept Vacuum Equipment Mar-98 Nov-98 Sep-98 Jan-99Initiate Facility Shakedown Mar-98 Nov-98 Mar-99 Jan-99
Hanford Livingston
24-Apr-02 Physics 237b 10
LIGOcosts & commitments
24-Apr-02 Physics 237b 13
LIGOcontingency vs percent complete
24-Apr-02 Physics 237b 14
Staffinghistory
24-Apr-02 Physics 237b 15
Staffinglabor distribution projections
LIGOStatus
24-Apr-02 Physics 237b 17
LIGO Hanford Observatory
24-Apr-02 Physics 237b 18
Signals in CoincidenceHanford Observatory
LivingstonObservatory
24-Apr-02 Physics 237b 19
Detection Strategycoincidences
! 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
24-Apr-02 Physics 237b 20
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
24-Apr-02 Physics 237b 21
LIGO Facilitiesbeam tube enclosure
• minimal enclosure
• reinforced concrete
• no services
24-Apr-02 Physics 237b 22
LIGObeam 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 stainless50 km of weld
NO LEAKS !!
24-Apr-02 Physics 237b 23
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
24-Apr-02 Physics 237b 24
Beam Tube bakeout
• I = 2000 amps for ~ 1 week
• no leaks !!
• final vacuum at level where not limiting noise, even for future detectors
24-Apr-02 Physics 237b 25
LIGOvacuum equipment
24-Apr-02 Physics 237b 26
Vacuum Chambersvibration 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
24-Apr-02 Physics 237b 27
Seismic Isolationsprings and masses
damped springcross section
24-Apr-02 Physics 237b 28
Seismic Isolationsuspension system
• support structure is welded tubular stainless steel
• suspension wire is 0.31 mm diameter steel music wire
• fundamental violin mode frequency of 340 Hz
suspension assembly for a core optic
24-Apr-02 Physics 237b 30
LIGO Noise Curvesmodeled sensitivity
wire resonances
24-Apr-02 Physics 237b 31
Core Opticsfused silica
Caltech data CSIRO data
! Surface uniformity < 1 nm rms! Scatter < 50 ppm! Absorption < 2 ppm! ROC matched < 3%! Internal mode Q’s > 2 x 106
24-Apr-02 Physics 237b 32
Core Optics installation and alignment
24-Apr-02 Physics 237b 33
ITMx Internal Mode Ringdowns
14.3737 kHz; Q = 1.2e+79.675 kHz; Q ~ 6e+5
24-Apr-02 Physics 237b 34
LIGO laser
! Nd:YAG
! 1.064 µµµµm
! Output power > 8W in TEM00 mode
24-Apr-02 Physics 237b 35
Commissioning configurations
! Mode cleaner and Pre-Stabilized Laser! 2km one-arm cavity ! short Michelson interferometer studies
! Lock entire Michelson Fabry-Perot interferometer
“First Lock”
24-Apr-02 Physics 237b 36
Why is Locking Difficult?
One meter, about 40 inches
Human hair, about 100 microns000,10÷
Wavelength of light, about 1 micron100÷
LIGO sensitivity, 10-18 meter000,1÷
Nuclear diameter, 10-15 meter000,100÷
Atomic diameter, 10-10 meter000,10÷
Earthtides, about 100 microns
Microseismic motion, about 1 micron
Precision required to lock, about 10-10 meter
24-Apr-02 Physics 237b 37
Laserstabilization
IO
10-WattLaser
PSL Interferometer
15m4 km
Tidal Wideband
! 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
10-1 Hz/Hz1/2 10-4 Hz/ Hz1/2 10-7 Hz/ Hz1/2
24-Apr-02 Physics 237b 38
Prestabalized Laserperformance
! > 18,000 hours continuous operation
! Frequency and lock very robust
! TEM00 power > 8 watts
! Non-TEM00 power < 10%
24-Apr-02 Physics 237b 39
LIGO“first lock”
signal
LaserX Arm
Y Arm
Composite Video
24-Apr-02 Physics 237b 40
Watching the Interferometer Lock
signalX Arm
Y Arm
Laser
X arm
Anti-symmetricport
Y arm
Reflected light
2 min
24-Apr-02 Physics 237b 41
Lock Acquisition
24-Apr-02 Physics 237b 42
Engineering Test Run2 weeks – Jan 02
PRELIMINARY
2 Km Hanford
4 Km Livingston
4 Km Hanford
24-Apr-02 Physics 237b 43
Strain Spectra for E7comparison with design sensitivity
LIGO I Design
24-Apr-02 Physics 237b 47
Detecting the Earth Tides Sun and Moon
24-Apr-02 Physics 237b 62
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
24-Apr-02 Physics 237b 63
LIGOconclusions
! 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 2007