Advanced LIGO the Laser Interferometer Gravitational-wave Observatory The Next Gravitational-Wave Observatory

Transcription

1 Advanced LIGO the Laser Interferometer Gravitational-wave Observatory The Next Gravitational-Wave Observatory Brian Lantz, for the LSC (40+ institutions, hundreds of people) SLAC Instrumentation Series, Feb 20, 2008 black hole image courtesy of LISA,

2 2 A LIGO Instrument Overview This afternoon: - Introduction to Gravitational waves and their detection. - Performance of Initial LIGO (amazing, but...), plans for Enhanced LIGO, and predictions for Advanced LIGO (regular detections?). - Discussion of a few of the new instrument s subsystems. optics, seismic isolation, laser,

3 3 What is a Gravitational Wave?

4 3 What is a Gravitational Wave? A stationary electron has an electric field, and accelerating the electron creates waves. A stationary mass has a gravitational field, and accelerating the mass creates waves. But, gravitational forces are relatively weak

5 3 What is a Gravitational Wave? A stationary electron has an electric field, and accelerating the electron creates waves. A stationary mass has a gravitational field, and accelerating the mass creates waves. But, gravitational forces are relatively weak (f or electron and proton) electricalf orce gravitationalforce

6 3 What is a Gravitational Wave? A stationary electron has an electric field, and accelerating the electron creates waves. A stationary mass has a gravitational field, and accelerating the mass creates waves. But, gravitational forces are relatively weak spinning a barbell in the lab is hopeless, h~ kg 2 m 1000 kg 1 khz

7 Astronomy 4 How about Neutron stars? Hulse and Taylor 93. (PSR ) and in 300 MYears... The Swan-song (Weisberg and Taylor)

8 Black Hole Collisions 5 Black hole collisions courtesy of Kip Thorne, G030311, June 2003

9 Binary black holes 6 Centrella et. al, NASA Goddard Spaceflight center

10 Binary black holes 6 Centrella et. al, NASA Goddard Spaceflight center

11 7 Supernovas and remnants 1987a Crab Nebula, supernova in 1054, now a spinning neutron star 1987a HST image from HST photo courtesy of ESA

12 The LIGO concept 8

13 The LIGO concept 9 A few interferometer tricks: - long arms, because h = dl/l - Fabry-Perot cavities in the arms - Power recycling = more power - Signal recycling = tuning to enhanced certain frequencies (new for AdLIGO, already in GEO600) =dual-recycled Fabry-Perot Michelson Interferometer

14 LIGO facilities 10 LIGO has 2 US sites, funded by NSF. Part of international network, including GEO600, VIRGO, TAMA, ACIGA Livingston, LA Hanford, WA photos from

15 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

16 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

17 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

18 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

19 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

20 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

21 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

22 The LIGO vacuum 11 equipment drawing courtesy of Oddvar Spjeld

23 Initial LIGO sensitivity 12

24 Finished S5 13 We recently completed Science run #5 1 year of triple coincidence data at design sensitivity completed on Sept 30, 2007, 2400 UTC Several upper limit papers on partial data exist. Full data set is now being analyzed No detections.

25 Initial LIGO NS/NS range ~15 MPc (50e6 lightyears) The Seeing 14 image by R. Powell

26 Initial LIGO NS/NS range ~15 MPc (50e6 lightyears) The Seeing 14 image by R. Powell

27 3 detector network range for NS/NS of 300 MPc 15 image by R. Powell image by R. Powell

28 The Advanced LIGO proposal 16 Proposal to the NSF to improve the sensitivity of existing observatories to dramatically enhance the astrophysics. Part of an international network: GEO600 (Germany-UK), VIRGO (Italy-France), TAMA (Japan), ACIGA (Australia). Same facilities as Initial LIGO, but with new detectors. Requested construction funding from NSF in FY2008. Development is very far along, carried out by many partners. Project cost $186 M (US, 2006$) NSF $172 M AEI to supply the lasers. Already funded by Max Planck Gesellschaft for development and for $7.1M in 2006$ for fabrication. UK/GEO for suspensions and core optics Already funded by PPARC for development and for $6.87M in 2006$ for fabrication.

29 LIGO Scientific Collaboration 17 Australian Consortium for Interferometric Gravitational Astronomy The Univ. of Adelaide Andrews University The Australian National Univ. The University of Birmingham California Inst. of Technology Cardiff University Carleton College Charles Sturt Univ. Columbia University Embry Riddle Aeronautical Univ. Eötvös Loránd University University of Florida German/British Collaboration for the Detection of Gravitational Waves University of Glasgow Goddard Space Flight Center Leibniz Universität Hannover Hobart & William Smith Colleges Inst. of Applied Physics of the Russian Academy of Sciences Polish Academy of Sciences India Inter-University Centre for Astronomy and Astrophysics Louisiana State University Louisiana Tech University Loyola University New Orleans University of Maryland Max Planck Institute for Gravitational Physics University of Michigan University of Minnesota The University of Mississippi Massachusetts Inst. of Technology Monash University Montana State University Moscow State University National Astronomical Observatory of Japan Northwestern University University of Oregon Pennsylvania State University Rochester Inst. of Technology Rutherford Appleton Lab University of Rochester San Jose State University Univ. of Sannio at Benevento, and Univ. of Salerno University of Sheffield University of Southampton Southeastern Louisiana Univ. Southern Univ. and A&M College Stanford University University of Strathclyde Syracuse University Univ. of Texas at Austin Univ. of Texas at Brownsville Trinity University Universitat de les Illes Balears Univ. of Massachusetts Amherst University of Western Australia Univ. of Wisconsin-Milwaukee Washington State University University of Washington

30 The Advanced LIGO proposal 18 Milestones: Advanced LIGO funding start in FY2008; fabrication, assembly, and stand-alone testing of detector components Advanced LIGO starts decommissioning initial LIGO instruments in early 2011, installing new detector components from stockpile. First Advanced LIGO interferometer accepted in early 2013, second and third in mid Construction project completes Commissioning of instruments, Engineering runs starting in 2014, Science in Enhanced LIGO upgrade

31 Advanced LIGO Preparation 19 Enhanced LIGO We are currently installing a modest set of upgrades funded with Initial LIGO resources. Make the best use the time before Gain experience with Advanced LIGO technology - Take laser from 10 W to 30 W, - Install the new DC readout scheme, - Install 1 new style seismic isolation system, - Try the new computing/ control infrastructure. Make a factor of 2 improvement in the sensitivity. (about 6-7 times more galaxies in range). Enhanced LIGO upgrade

32 Sources 20 Neutron star and Black hole binaries inspiral merger Spinning NS s LMXB known pulsars unknown? Birth of NS (supernovas) tumbling convection Stochastic Background remnants of the big bang h(f) andh s (f) / Hz 1/ Ω=10-9 Vela Spindown Upper Limit 10 Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Ω=10-11 Ω=10-7 Crab Spindown Upper Limit BH/BH Inspiral 400Mpc Merger Merger WB Adv LIGO 20Mo/20M o BH/BH Merger, z=1 Courtesy of Kip Thorne Initial LIGO Sco X-1 LMXBs Known Pulsar ε=10-6, r=10kpc ε=10-7 r=10kpc frequency, Hz

33 Advanced LIGO - Technology 21 Technical Improvements Vela Spindown Upper Limit Ω=10-7 Crab Spindown Upper Limit h(f) andh s (f) / Hz 1/ Ω= Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 BH/BH Inspiral 400Mpc NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Merger Merger Initial LIGO Sco X-1 Known Pulsar ε=10-6, r=10kpc Ω=10-11 WB Adv LIGO ε=10-7 r=10kpc LMXBs Mo/20M o BH/BH Merger, z= frequency, Hz

34 Advanced LIGO - Technology 21 Technical Improvements Environmental Isolation: platforms & pendulums h(f) andh s (f) / Hz 1/ Ω=10-9 Vela Spindown Upper Limit Ω= Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 Crab Spindown Upper Limit BH/BH Inspiral 400Mpc NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Merger Merger Initial LIGO Sco X-1 Known Pulsar ε=10-6, r=10kpc Ω=10-11 WB Adv LIGO ε=10-7 r=10kpc LMXBs Mo/20M o BH/BH Merger, z= frequency, Hz

35 Advanced LIGO - Technology 21 Technical Improvements Environmental Isolation: platforms & pendulums Thermal Noise control: suspensions & coatings h(f) andh s (f) / Hz 1/ Ω=10-9 Vela Spindown Upper Limit Ω= Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 Crab Spindown Upper Limit BH/BH Inspiral 400Mpc NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Merger Merger Initial LIGO Sco X-1 Known Pulsar ε=10-6, r=10kpc Ω=10-11 WB Adv LIGO ε=10-7 r=10kpc LMXBs Mo/20M o BH/BH Merger, z= frequency, Hz

36 Advanced LIGO - Technology 21 Technical Improvements Environmental Isolation: platforms & pendulums Thermal Noise control: suspensions & coatings h(f) andh s (f) / Hz 1/2 More Power new 180 W laser 830 kw circulating in arms Ω=10-9 Vela Spindown Upper Limit 10 Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Ω=10-11 Ω=10-7 Crab Spindown Upper Limit BH/BH Inspiral 400Mpc Merger Merger WB Adv LIGO Initial LIGO Sco X-1 Known Pulsar ε=10-6, r=10kpc ε=10-7 r=10kpc LMXBs Mo/20M o BH/BH Merger, z= frequency, Hz

37 Advanced LIGO - Technology 21 Technical Improvements Environmental Isolation: platforms & pendulums Thermal Noise control: suspensions & coatings h(f) andh s (f) / Hz 1/2 More Power new 180 W laser 830 kw circulating in arms Signal recycling gives tunable response Ω=10-9 Vela Spindown Upper Limit 10 Mo /10M o BH/BH inspiral 100Mpc 50Mo /50M o BH/BH Merger, z=2 NB Adv LIGO NS/NS Inspiral 300Mpc; NS/BH Inspiral 650Mpc BH/BH Inspiral, z=0.4 Ω=10-11 Ω=10-7 Crab Spindown Upper Limit BH/BH Inspiral 400Mpc Merger Merger WB Adv LIGO Initial LIGO Sco X-1 LMXBs Known Pulsar ε=10-6, r=10kpc ε=10-7 r=10kpc Mo/20M o BH/BH Merger, z= frequency, Hz

38 end station end station Reflections of the Technology 22 in a piece of glass 4km arm cavity Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz 4km arm cavity corner

39 end station end station Reflections of the Technology 22 in a piece of glass 4km arm cavity Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz 4km arm cavity corner

40 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz 8/;:&),$/.$<,), 4km arm cavity corner

41 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz Below 10 Hz: Seismic Isolation 8/;:&),$/.$<,), 4km arm cavity corner

42 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz Below 10 Hz: Seismic Isolation 8/;:&),$/.$<,), 4km arm cavity corner

43 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz Below 10 Hz: Seismic Isolation Hz: Coating Noise 8/;:&),$/.$<,), 4km arm cavity corner

44 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz Below 10 Hz: Seismic Isolation Hz: Coating Noise Above 200 Hz: Shot Noise 8/;:&),$/.$<,), 4km arm cavity corner

45 Reflections of the Technology 22 in a piece of glass 4km arm cavity end station end station Optic motion should be limited by fundamental processes - - goal of m/hz at 10 Hz Below 10 Hz: Seismic Isolation Hz: Coating Noise Above 200 Hz: Shot Noise 8/;:&),$/.$<,), 4km arm cavity corner

46 Seismic Isolation & 23 Alignment Isolation of the test mass 10 Hz motion test mass 1x10-19 m/hz ground ~4x10-10 m/hz rms length variation <1x10-14 m 7 layers of isolation

47 Seismic Isolation & 23 Alignment Isolation of the test mass 10 Hz motion test mass 1x10-19 m/hz ground ~4x10-10 m/hz rms length variation <1x10-14 m 7 layers of isolation 4 stage pendulum 1x10-19 m/hz near 10 Hz

48 Seismic Isolation & 23 Alignment Isolation of the test mass 10 Hz motion test mass 1x10-19 m/hz ground ~4x10-10 m/hz rms length variation <1x10-14 m 7 layers of isolation 4 stage pendulum 2 stage active isolation table 3x10-12 m/hz at 10 Hz 1x10-19 m/hz near 10 Hz

49 Seismic Isolation & 23 Alignment Isolation of the test mass 10 Hz motion test mass 1x10-19 m/hz ground ~4x10-10 m/hz rms length variation <1x10-14 m ~4x10-10 m/hz at 10 Hz 7 layers of isolation 4 stage pendulum 2 stage active isolation table 1 stage Hydraulic External Pre-Isolator 1x10-19 m/hz near 10 Hz

50 Seismic Isolation & 24 Alignment - HEPI > Range of +/- 1 mm > Easily holds 1e3 N (400 lbs) static offset > Quiet (<1 nm/hz at 1 Hz)

51 Seismic Isolation & 24 Alignment - HEPI > Range of +/- 1 mm > Easily holds 1e3 N (400 lbs) static offset > Quiet (<1 nm/hz at 1 Hz) > 1 Vert, 1 Horz per pier for full 6DOF control > springs carry static load > Feed-forward ground sensors and feed-back local sensors for alignment and isolation. > Installed and running at LLO.

52 Seismic Isolation & 25 Alignment - HEPI Velocity ASD (m/s/hz 1/2 ) or rms (m/s) X-arm length disturbance, noisy afternoon rms - HEPI off rms - lock threshold rms - HEPI on HEPI on, sensor correction on ", rms HEPI off ", rms Run time in S4 increased to 74.5%, from 21.8% Frequency (Hz)

53 Seismic Isolation & 26 Alignment - platform Technology demonstrator designed and installed in Stanford vacuum system (ETF). mechanical system designed for approximately LIGO size platform, with approx half-size payload capacity. most sensors and actuators as final design. True prototype being installed at MIT for full scale, UHV, tests with suspension systems. modal frequencies designed to be > 150 Hz to accommodate " 50 Hz servo unity-gain point. modeling of 6 x 6 DOF stiffness at low frequencies. We design horizontal-tilt cross coupling < 1/500 rad/m. new design for rigid and strong stops, to exactly position stages and restrict motion during earthquakes. can accommodate " 800 kg payload. Servo and mechanical design need to tolerate mechanically reactive massive payload

54 Seismic Isolation & 26 Alignment - platform Technology demonstrator designed and installed in Stanford vacuum system (ETF). mechanical system designed for approximately LIGO size platform, with approx half-size payload capacity. most sensors and actuators as final design. True prototype being installed at MIT for full scale, UHV, tests with suspension systems. modal frequencies designed to be > 150 Hz to accommodate " 50 Hz servo unity-gain point. modeling of 6 x 6 DOF stiffness at low frequencies. We design horizontal-tilt cross coupling < 1/500 rad/m. new design for rigid and strong stops, to exactly position stages and restrict motion during earthquakes. can accommodate " 800 kg payload. Servo and mechanical design need to tolerate mechanically reactive massive payload

55 Seismic Isolation & 26 Alignment - platform Technology demonstrator designed and installed in Stanford vacuum system (ETF). mechanical system designed for approximately LIGO size platform, with approx half-size payload capacity. most sensors and actuators as final design. True prototype being installed at MIT for full scale, UHV, tests with suspension systems. modal frequencies designed to be > 150 Hz to accommodate " 50 Hz servo unity-gain point. modeling of 6 x 6 DOF stiffness at low frequencies. We design horizontal-tilt cross coupling < 1/500 rad/m. new design for rigid and strong stops, to exactly position stages and restrict motion during earthquakes. can accommodate " 800 kg payload. Servo and mechanical design need to tolerate mechanically reactive massive payload

56 Stage 2 X Seismic Isolation & 27 Alignment - platform Isolation requirement: 100 at 1 Hz (met) 3000 at 10 Hz (design mod) We modified the LASTI prototype to increase vertical passive isolation at 10 Hz, based on these tests. Ground X goal Stage 1 X

57 Stage 2 X Seismic Isolation & 27 Alignment - platform Isolation requirement: 100 at 1 Hz (met) 3000 at 10 Hz (design mod) We modified the LASTI prototype to increase vertical passive isolation at 10 Hz, based on these tests. Ground X LASTI prototype now being tested at MIT. goal Stage 1 X

58 Single stage isolator 28 Bolted aluminum structure Suspended by 3 blade springs & wires isolation of above 1 Hz for auxiliary optics designed for auxiliary optics - input and output mode cleaners, - power and signal recycling mirrors, - beam expanding telescope, - GW signal readout bench to be installed into Enhanced LIGO

59 Single stage isolator 28 Bolted aluminum structure Suspended by 3 blade springs & wires isolation of above 1 Hz for auxiliary optics designed for auxiliary optics - input and output mode cleaners, - power and signal recycling mirrors, - beam expanding telescope, - GW signal readout bench to be installed into Enhanced LIGO next week

60 Single stage isolator 28 Bolted aluminum structure Suspended by 3 blade springs & wires isolation of above 1 Hz for auxiliary optics designed for auxiliary optics - input and output mode cleaners, - power and signal recycling mirrors, - beam expanding telescope, - GW signal readout bench to be installed into Enhanced LIGO next week

61 Pendulum Suspension Suspensions material from N. Robertson, GEO600, and the SUS team Multiple-pendulums for control flexibility & seismic attenuation 29 (Based on GEO600 design) 8/;:&),$/.$<,), Drawings courtesy of Calum Torrie and GEO600 Each stage gives ~1/f2 isolation above the natural frequency. More that 1e6 at 10 Hz. Test masses: Synthetic fused silica, 40 kg, 34 cm dia.» Q # 1e7» low optical absorption Final suspensions are fused silica, joined to form monolithic final stages. Thermal vibrations at the optical surface set the performance limit of the suspension.

62 Pendulum Suspension 30 Multiple-pendulums for control flexibility & seismic attenuation 8/;:&),$/.$<,), Each stage gives ~1/f2 isolation above the natural frequency. More that 1e6 at 10 Hz. (Based on GEO600 design) Drawings courtesy of Calum Torrie and GEO600 silicate bonding creates a monolithic final stage

63 Pendulum Suspension 30 Multiple-pendulums for control flexibility & seismic attenuation 8/;:&),$/.$<,), Each stage gives ~1/f2 isolation above the natural frequency. More that 1e6 at 10 Hz. (Based on GEO600 design) Drawings courtesy of Calum Torrie and GEO600 silicate bonding creates a monolithic final stage

64 Pendulum Suspension Quadruple pendulum now installed at MIT with metal mirrors. Interaction tests between pendulum and platform have begun Ribbon pulling machine at the University of Glasgow 31

65 Test Mass Requirements 32 Mass Dimensions Surface figure Micro-roughness Double-pass optical homogeneity Bulk absorption (Heraeus Suprasil 311) 40 kg, fused silica 340 mm x 200 mm < 1 nm rms < 0.1 nm rms < 20 nm rms, < 3 ppm/cm Bulk mechanical loss < 3x10-9 Optical coating: Titania doped Tantala/ silica Optical coating absorption Optical coating mechanical loss Optical coating scatter Arm cavity optical loss / round trip < 0.5 ppm(required) < 0.2 ppm(goal) < 2x10-4 (required) < 3x10-5 (goal) < 2 ppm(required) < 1 ppm(goal) < 75 ppm courtesy of G. Harry, S. Rowan, and the optics working group

66 Test Mass Requirements 32 Mass Dimensions Surface figure Micro-roughness Double-pass optical homogeneity 40 kg, fused silica 340 mm x 200 mm < 1 nm rms < 0.1 nm rms < 20 nm rms, Bulk absorption (Heraeus Suprasil 311) < 3 ppm/cm good enough for Thermal Comp. System Bulk mechanical loss < 3x10-9 Optical coating: Titania doped Tantala/ silica Optical coating absorption Optical coating mechanical loss Optical coating scatter Arm cavity optical loss / round trip < 0.5 ppm(required) < 0.2 ppm(goal) < 2x10-4 (required) < 3x10-5 (goal) < 2 ppm(required) < 1 ppm(goal) < 75 ppm courtesy of G. Harry, S. Rowan, and the optics working group

67 Test Mass Requirements 32 Mass Dimensions Surface figure Micro-roughness Double-pass optical homogeneity 40 kg, fused silica 340 mm x 200 mm < 1 nm rms < 0.1 nm rms < 20 nm rms, Bulk absorption (Heraeus Suprasil 311) < 3 ppm/cm good enough for Thermal Comp. System Bulk mechanical loss < 3x10-9 Optical coating: Titania doped Tantala/ silica Optical coating absorption Optical coating mechanical loss Optical coating scatter Arm cavity optical loss / round trip < 0.5 ppm(required) < 0.2 ppm(goal) < 2x10-4 (required) < 3x10-5 (goal) < 2 ppm(required) < 1 ppm(goal) < 75 ppm courtesy of G. Harry, S. Rowan, and the optics working group

68 Test Mass Requirements 32 Mass Dimensions Surface figure Micro-roughness Double-pass optical homogeneity 40 kg, fused silica 340 mm x 200 mm < 1 nm rms < 0.1 nm rms < 20 nm rms, Bulk absorption (Heraeus Suprasil 311) < 3 ppm/cm good enough for Thermal Comp. System Bulk mechanical loss < 3x10-9 Optical coating: Titania doped Tantala/ silica Optical coating absorption < 0.5 ppm(required) < 0.2 ppm(goal) samples at 0.4 ppm Optical coating mechanical loss Optical coating scatter Arm cavity optical loss / round trip < 2x10-4 (required) < 3x10-5 (goal) < 2 ppm(required) < 1 ppm(goal) < 75 ppm measured 8.5x10-5 not yet... courtesy of G. Harry, S. Rowan, and the optics working group

69 Test Mass Requirements 32 Mass Dimensions Surface figure Micro-roughness Double-pass optical homogeneity 40 kg, fused silica 340 mm x 200 mm < 1 nm rms < 0.1 nm rms < 20 nm rms, Bulk absorption (Heraeus Suprasil 311) < 3 ppm/cm good enough for Thermal Comp. System Bulk mechanical loss < 3x10-9 Optical coating: Titania doped Tantala/ silica Optical coating absorption < 0.5 ppm(required) < 0.2 ppm(goal) samples at 0.4 ppm Optical coating mechanical loss Optical coating scatter Arm cavity optical loss / round trip < 2x10-4 (required) < 3x10-5 (goal) < 2 ppm(required) < 1 ppm(goal) < 75 ppm measured 8.5x10-5 not yet... courtesy of G. Harry, S. Rowan, and the optics working group

70 Pendulum Suspension 33 equivalent single mass motion, (m/rthz) Predicted motion of the Advanced LIGO Test Mass Motion of the Test Mass with Proposed Mods to ASI design courtesy of Brian Lantz % noise (max) 50% noise (max) 95% noise worst case 50% noise worst case long. motion from SEI total long. motion from SEI Z long. motion from SEI X long. from SUS Thermal Newtonian Background thermal seismic freq (Hz) created by show_perf on 03Aug2005 1e-19 m/hz

71 Power, Optics, and 34 Interferometers

72 Power, Optics, and 34 Interferometers 180 W laser

73 High Power Laser 180 W with good beam shape 1064 nm (YAG) very low intensity and frequency noise Developed by AEI (Max-Planck Institute, Hanover) & Laser Zentrum Hanover (LZH) stable front end determines laser frequency and frequency fluctuations. (NPRO & 4 rod Nd:YVO) high power stage, Injection seeded ring oscillator determines power, power fluctuations, and beam shape. high-power injection-locked oscillator 30 watt seed laser 35 Laser material from B. Wilke, P. Wessels, GEO600, AEI, LZH

74 High Power 36 Laser W output power (91.5% in TEM00) good spatial profile power fluctuations close to requirement. 37 W seed laser installed at one and about to be installed at second site for Enhanced LIGO. Power fluctuations Beam profile of high power beam Still to Verify: RIN at low frequency preparing to build Engineering Prototype

75 Tuning Instrument noise floor set by thermal noise (coatings) & unified quantum noise (above 10 Hz) Strain noise (Hz -1/2 ) seismic total newtonian background quantum suspension thermal residual gas mirror thermal Frequency (Hz)

76 Tuning 38 Signal recycling mirror makes it possible to tune the response to your favorite source Strain noise (Hz -1/2 ) seismic moving bump pick your favorite source lower power & tuned for low frequencies total tuned for higher frequencies newtonian background quantum suspension thermal residual gas fake curves for tightly tuned pulsar searches mirror thermal Frequency (Hz) When we start measuring gravitational waves, this flexible instrument can be directed towards many different astrophysical goals.

77 and more End-to-end model Sensing and control for all length and angle DOFs Big computing pipeline for both instrument control and for data analysis. output mode cleaner (CIT 40 meter lab) high power input optics (Univ. Florida) 40 m lab & Thermal noise interferometer at Caltech, LASTI at MIT, high-power test facility at Gingin, 10 meter lab at Univ. Glasgow, ETF at Stanford, the LIGO and GEO observatories...

78 40 in Conclusion... LIGO science collaboration is large and active, We ve developed a tremendous amount of new technology, We now have the technology in hand to make a fantastic new instrument, and We are ready to start the construction. The astrophysics will be great

79 41 Data Rate Advanced LIGO Initial LIGO channel cnt. (LHO, LLO, total) = = 1938 Acquisition rate = 46 MB/s = 17.4 MB/s Recorded rate = 20.6 MB/s = 9.9 MB/s