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

LIGO-G Z 2 Table of Content  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

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

LIGO-G Z 4 Seismic Isolation Optics suspension:  Single steel wire pendulum

LIGO-G Z 5 Seismic Isolation 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

LIGO-G Z 6 Seismic Isolation 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

LIGO-G Z 7 Seismic Isolation  Vibration Isolation System: »4 layer passive isolation stack

LIGO-G Z 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). Solution: HEPI ( Hydraulic Actuator External Pre-Isolator) Low Duty cycle until S4

LIGO-G Z 9 Livingston Seismic Problems Caused by human activity: Cars, Trains, Trucks, Logging, Well Drilling, Oil Pipeline Amplified by internal isolation stack resonances 99 Ocean activity, hurricanes

LIGO-G Z 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

LIGO-G Z 11 Helical Spring Vertical Actuator Horizontal Actuator Crossbeam Pier Input Test Mass Chamber Improved Duty cycle: S3S4 L1:22%75% H1:69%81% H2:63%81%

LIGO-G Z 12 Wavefront Sensing  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)  Main benefit: reduces the orthogonal phase signal at the anti-symmetric port (ASI), allowing higher power operation

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LIGO-G Z 14 Thermal Correction System CO 2 Laser ? Over-heat mask Under-heat mask Inhomogeneous mask ZnSe Viewport Over-heat pattern Under-heat pattern Raw Heating 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?)

LIGO-G Z 15 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. ITMXITMY Before35 mW/W13.5 mW/W Now< 3 mW/W3 mW/W

LIGO-G Z 16 Laser Situation 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:

LIGO-G Z 17 Hardware Status 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

LIGO-G Z 18 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)

LIGO-G Z 19 Sensitivities Initial LIGO Design S1 (L1) 1 st Science Run end Sept days S2 (L1) 2 nd Science Run end Apr days S3 (H1) 3 rd Science Run end Jan days

LIGO-G Z 20 Lets look into this noise 3.5 Mpc 7.3 Mpc 8.4 Mpc

LIGO-G Z 21 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

LIGO-G Z 22 BANG!  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 Data Analysis

LIGO-G Z 23 Science  S1: Aug. 23 – Sep , 17 days » Setting upper limits on the strength of periodic gravitational waves from PSR J using the first science data from the GEO 600 and LIGO detectors, Phys. Rev. D69: (2004). » First upper limits from LIGO on gravitational wave bursts, Phys. Rev. D69: (2004). » Analysis of LIGO data for gravitational waves from binary neutron stars, Phys. Rev. D69: (2004). » Analysis of first LIGO science data for stochastic gravitational waves, Phys. Rev. D69: (2004).

LIGO-G Z 24 Science  S2 Feb. 14 – Apr. 14, 2003, 59 days »Limits on gravitational-wave emission from selected pulsars using LIGO data, Phys. Rev. Lett 94: (2004). »Search for gravitational waves associated with the gamma ray burst GRB using the LIGO detectors, Phys. Rev. D, Vol. 72, (2005) »Search for gravitational waves from galactic and extra-galactic binary neutron stars, gr-qc (2005) »Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo, gr-qc (2005) »Upper limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts, gr-qc »Upper limits on gravitational wave bursts in LIGO’s second science run, gr-qc (2005)  S3: October 31, 2003 – January 9, 2004, 70 days  S4: February 2, 2005 – March 23, 2005, 50 days

LIGO-G Z 25  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 S5-Run

LIGO-G Z 26 Duty cycle RunS2S3S4 S5 Target (proposed) SRD goal L137%22%75%85%90% H174%69%81%85%90% H258%63%81%85%90% 3-way22%16%57%70%75%

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LIGO-G Z 28 Latest news from H1: Achieved 11.6Mpc range! Runs now routinely above 10MPc! Peter Saulson 09/04/05

LIGO-G Z 29 LIGO Science Collaboration A family photo