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Guido Mueller University of Florida For the LIGO Scientific Collaboration

LIGO. Status Report LIGO. Guido Mueller University of Florida For the LIGO Scientific Collaboration. ESF Exploratory Workshop Perugia, Italy September 21 st –23 rd , 2005. Layout Seismic Isolation Suspension system HEPI Interferometer

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Guido Mueller University of Florida For the LIGO Scientific Collaboration

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  1. LIGO Status Report LIGO Guido Mueller University of Florida For the LIGO Scientific Collaboration ESF Exploratory Workshop Perugia, Italy September 21st –23rd, 2005

  2. Layout Seismic Isolation Suspension system HEPI Interferometer Wavefront Sensor Thermal Correction System (TCS) Laser situation Science Output Sensitivities/Papers at different Science Runs S5-Plans Table of Content

  3. LIGO Layout Power-recycled, cavity-enhanced Michelson Interferometer • Arm Cavities: • Livingston: 4km long • Hanford: 4km and 2km long • TITM = 2.7%, Finesse ~ 115 • Power Recycling mirror: • TPR = 2.7%, Gain ~ 50 • Mirrors: • Material: Fused Silica • 25cm diameter • 10cm thick • Wedged (~2deg) 15kW 225W 5W

  4. Optics suspension: Single steel wire pendulum Seismic Isolation

  5. Optics suspension: Single steel wire pendulum Normal modes: Pendulum: ~0.74 Hz Yaw mode: ~0.5 Hz Pitch mode: ~0.6 Hz Roll mode: ~18 Hz Violin mode: ~345 Hz Coil-magnet actuation Magnet on optic Coil on support frame Includes shadow sensor Seismic Isolation

  6. Optics suspension: Single steel wire pendulum Normal modes: Pendulum: ~0.74 Hz Yaw mode: ~0.5 Hz Pitch mode: ~0.6 Hz Roll mode: ~18 Hz Violin mode: ~340 Hz Coil-magnet actuation Magnet on optic Coil on support frame Includes shadow sensor Seismic Isolation

  7. Vibration Isolation System: 4 layer passive isolation stack Seismic Isolation

  8. Seismic Isolation • Attenuation of 120dB • above 50 Hz • High-Q resonances • between 1.5 and 12 Hz • amplify external • noise (falling trees and • trains at LLO). Low Duty cycle until S4 Solution: HEPI (Hydraulic Actuator External Pre-Isolator)

  9. Livingston Seismic Problems Caused by human activity: Cars, Trains, Trucks, Logging, Well Drilling, Oil Pipeline Amplified by internal isolation stack resonances Ocean activity, hurricanes 9 9

  10. HEPI Quiet Hydraulic Acuators 3 Sensors, 2 crossovers Position sensors for DC lock Ground sensor for low freq. correction Payload geophone for high frequencies

  11. Crossbeam HorizontalActuator Helical Spring Vertical Actuator Pier Input Test Mass Chamber Improved Duty cycle: S3 S4 L1: 22% 75% H1: 69% 81% H2: 63% 81%

  12. System measures & controls mirror (core optic) pitch & yaw angles Complication: each sensor is sensitive to alignment of multiple mirrors Before and during S4, the servo bandwidths was very low Current status: Mixing of control signals is carefully tuned to decouple the WFS channels from each other Increased gain and bandwidth (2-4 Hz for ITM and ETM) Wavefront Sensing • Main benefit: reduces the orthogonal phase signal at the anti-symmetric port (ASI), allowing higher power operation

  13. ? Thermal Correction System ZnSe Viewport CO2 Laser Over-heat mask Under-heat mask Inhomogeneous mask Raw Heating pattern Over-heat pattern Under-heat pattern • TCS is very effective in correcting up to 100 mW of absorption in ITMs • Had still problems with 4k ITMX in Hanford (high absorption?)

  14. Thermal Correction System • Replaced ITMX in Hanford • Beam size measurements repeated. Power needed to correct thermal lensing: • Now, we can increase the input power into interferometer.

  15. Hanford: H1: Laser replaced in April 2004 Power output: 11W (without any degradation since April 04) H2: Original laser, running since October 1998 Replaced Master laser early this year Power output: 7W (scheduled for replacement soon) L1: Laser Situation

  16. Summary: Seismic Isolation now active (HEPI) Improved duty cycle Wavefront Sensors tuned and activated Larger bandwidth in control loops Enables higher power operation Thermal Correction System installed and “dirty” mirror replaced Enables higher power operation Hardware Status

  17. Data Runs S1 run: 17 days (August / September 2002) S2 run: 59 days (February—April 2003) S3 run: 70 days (October 2003 – January 2004) S4 run: 50 days (February – March 2005)

  18. Sensitivities S1 (L1) 1st Science Run end Sept. 2002 17 days S2 (L1) 2nd Science Run end Apr. 2003 59 days Initial LIGO Design S3 (H1) 3rd Science Run end Jan. 2004 70 days

  19. 3.5 Mpc 7.3 Mpc 8.4 Mpc Lets look into this noise

  20. Noise Upconversion Using HEPI, increase the suspension point motion at 1.5 Hz by a factor of 5 DARM noise increases by a factor of ~5 over a wide band

  21. BANG! Data Analysis • Binary systems • Neutron star – Neutron star • Black hole – Neutron star • Black hole – Black hole • Periodic Sources • Rotating pulsars • “Burst” Sources • Supernovae • Gamma ray bursters • ????? • Stochastic • Big Bang Background • Cosmic Strings

  22. Science • S1: Aug. 23 – Sep. 9 2002, 17 days • Setting upper limits on the strength of periodic gravitational waves from PSR J1939+2134 using the first science data from the GEO 600 and LIGO detectors, Phys. Rev. D69: 082004 (2004). • First upper limits from LIGO on gravitational wave bursts, Phys. Rev. D69: 102001 (2004). • Analysis of LIGO data for gravitational waves from binary neutron stars, Phys. Rev. D69: 122001 (2004). • Analysis of first LIGO science data for stochastic gravitational waves, Phys. Rev. D69: 122004 (2004).

  23. Science • S2 Feb. 14 – Apr. 14, 2003, 59 days • Limits on gravitational-wave emission from selected pulsars using LIGO data, Phys. Rev. Lett 94: 181103 (2004). • Search for gravitational waves associated with the gamma ray burst GRB030329 using the LIGO detectors,Phys. Rev. D, Vol. 72, 042002 (2005) • Search for gravitational waves from galactic and extra-galactic binary neutron stars, gr-qc 0505041 (2005) • Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo, gr-qc 0505042 (2005) • Upper limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts, gr-qc 0507081 • Upper limits on gravitational wave bursts in LIGO’s second science run, gr-qc 0505029 (2005) • S3: October 31, 2003 – January 9, 2004, 70 days • S4: February 2, 2005 – March 23, 2005, 50 days

  24. S5-Run • S5 goal: • one year’s data of coincident operation at the science goal sensitivity • Current Plan (LSC meeting in August) • Staggered start to S5 • L1 was expected to start with S5 on Oct 21 • Expect Hurricane related delays: • LLO is intact, up, and running • No Hotels for visiting scientists and local stuff has some problems at their homes (power outages, flooding, school closings, etc.) • H2 start Nov 4 • H1 schedule still uncertain—recovery from Test Mass replacement • Performance goals for S5 • H1, L1 over 10 Mpc inspiral range, H2 over 5 Mpc • Overall “Science content” ~ 100 times S4

  25. Duty cycle

  26. Latest news from H1: • Achieved 11.6Mpc range! • Runs now routinely above 10MPc! • Peter Saulson 09/04/05

  27. LIGO Science CollaborationA family photo

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