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Overview Ground-based Interferometers. Barry Barish Caltech Amaldi-6 20-June-05. LIGO Louisiana 4000m. Interferometer Detectors. TAMA Japan 300m. Virgo Italy 3000m. GEO Germany 600m. AIGO Australia future. LIGO Washington 2000m & 4000m. Network of Interferometers. LIGO. Virgo.
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Overview Ground-based Interferometers Barry Barish Caltech Amaldi-6 20-June-05
LIGO Louisiana 4000m Interferometer Detectors TAMA Japan 300m Virgo Italy 3000m GEO Germany 600m AIGO Australia future LIGO Washington 2000m & 4000m Amaldi-6 - Interferometer Overview - Barish
Network of Interferometers LIGO Virgo GEO TAMA AIGO decompose the polarization of gravitational waves detection confidence locate the sources Amaldi-6 - Interferometer Overview - Barish
As a wave passes, the arm lengths change in different ways…. Interferometer Concept …causing the interference pattern to change at the photodiode Suspended Masses Amaldi-6 - Interferometer Overview - Barish
Limiting Noise Sources • Seismic noise & vibration limit at low frequencies • Atomic vibrations (Thermal Noise) inside components limit at mid frequencies • Quantum nature of light (Shot Noise) limits at high frequencies • Myriad details of the lasers, electronics, etc., can make problems above these levels Amaldi-6 - Interferometer Overview - Barish
TAMA 300 Amaldi-6 - Interferometer Overview - Barish
Automated Data Taking in DT9 - Self-switching sub-system Logic circuit + Embedded micro processor Laser source control MC control Laser intensity stabilization Beam axes control Master-system (intelligent switching) PC + PCI boards + LabVIEW 64ch digital I/O 16ch A/D + 24ch D/A Lock acquisition Auto adjustment Interface with external system Amaldi-6 - Interferometer Overview - Barish
Sensitivity in DT9 Recycling gain: 4.5 Extended control band width for the laser frequency Improved strain sensitivity: h=1.7x10-21 /Hz1/2 @1kHz Amaldi-6 - Interferometer Overview - Barish
Observable distance for NS inspiral binaries TAMA Amaldi-6 - Interferometer Overview - Barish
TAMA Ringdown Analysis Amaldi-6 - Interferometer Overview - Barish
GEO 600 – Optical Layout Amaldi-6 - Interferometer Overview - Barish
GEO Sensitivity Evolution Amaldi-6 - Interferometer Overview - Barish
LIGO LIGO Hanford LIGO Livingston Amaldi-6 - Interferometer Overview - Barish
Evolution of LIGO Sensitivity Amaldi-6 - Interferometer Overview - Barish
Active Seismic Isolation at LLO • Hydraulic external pre-isolator (HEPI) • Signals from sensors on ground and cross-beam are blended and fed into hydraulic actuators • Status: • Installed on all 4 piers at each of nine vacuum chambers • System is operational Amaldi-6 - Interferometer Overview - Barish
Active Seismic Isolation at LLO • Can lock (and do commissioning work!) during daytime • Able to stay locked even when train passes nearby Amaldi-6 - Interferometer Overview - Barish
LIGO Livingston Sensitivity Amaldi-6 - Interferometer Overview - Barish
LIGO S4 – Best Performance Amaldi-6 - Interferometer Overview - Barish
Detection of Periodic Sources • Pulsars in our galaxy:“periodic” • search for observed neutron stars • all sky search (computing challenge) • r-modes • Frequency modulation of signal due to Earth’s motion relative to the Solar System Barycenter, intrinsic frequency changes. • Amplitude modulation due to the detector’s antenna pattern. Amaldi-6 - Interferometer Overview - Barish
LIGO – GEO Directed Pulsar Search 28 Radio Sources Amaldi-6 - Interferometer Overview - Barish
GEO-LIGO - Results • Lowest 95% UL on h0 = 1.7 10-24 (J1910-5959D) • Lowest bound on e = 4.5 10-6 (J2124-3358) • Crab pulsar: • h0 = 4.1 10-23 • e = 2.1 10-2 (~30 times spin-down upper limit) Crab pulsar Amaldi-6 - Interferometer Overview - Barish
Detection of Periodic Sources • Frequency modulationof signal due to Earth’s motion relative to the Solar System Barycenter, intrinsic frequency changes. • Pulsars in our galaxy NEW RESULT 28 known pulsars NO gravitational waves e < 10-5 – 10-6 (no mountains > 10 cm • Amplitude modulationdue to the detector’s antenna pattern. ALL SKY SEARCH enormous computing challenge Amaldi-6 - Interferometer Overview - Barish
Einstein@Home LIGO Pulsar Search using home pc’s BRUCE ALLEN Project Leader Univ of Wisconsin Milwaukee LIGO, UWM, AEI, APS http://einstein.phys.uwm.edu Amaldi-6 - Interferometer Overview - Barish
Virgo Amaldi-6 - Interferometer Overview - Barish
Thermal noise Virgo Seismic Performance Amaldi-6 - Interferometer Overview - Barish
Virgo - Sensitivity Goal Designed to have good sensitivity at low frequencies Amaldi-6 - Interferometer Overview - Barish
Extragalactic sensitivity to NS/NS coalescences 55 kpc Virgo Commissioning Amaldi-6 - Interferometer Overview - Barish
Advanced LIGO Multiple Suspensions Active Seismic Improved Optics Higher Power Laser Amaldi-6 - Interferometer Overview - Barish
Advanced LIGO • Enhanced Systems • laser • suspension • seismic isolation • test mass Rate Improvement~ 104 + narrow band optical configuration Amaldi-6 - Interferometer Overview - Barish
From Amaldi-6 Onwards • From Present GenerationAdvanced Detectors Next Generation Detectors (QND) • From 8 Mpc (NN inspiral)200 Mpc and beyond • From Upper LimitsSearches Detections • From Generic WaveformsSpecified Waveforms • From Single DetectorsGlobal Networks Amaldi-6 - Interferometer Overview - Barish