1. Searching for gravitational waves with lasers
Rick Savage
Caltech LIGO Hanford Observatory - Richland, WA

2. Black holes and time warps
Sept transferred to UCLA in Physics
Jan started working for F. Chen and N. Luhmann as undergraduate lab assistant (with Doug Cook)
1976 to plasma diagnostics with N. Luhmann, T. Peebles, H. Fetterman, et al.
1986 to graduate school in EE at UCLA with Chan Josh, Warren Mori, Ken Marsh, Chris Clayton, et al.
Masters thesis – Degenerate four-wave mixing in heated CO2 gas
PhD thesis – Frequency upshifting of electromagnetic radiation via an underdense relativistic ionization front
1992 to present - LIGO project at Caltech until 1997 then LIGO Hanford Observatory in Richland, WA
LIGO-G
UCLA Symposium Nov. 2009

3. LIGO: Laser Interferometer Gravitational-wave Observatory
Hanford, WA
MIT
3002 km
(L/c = 10 ms)
Caltech
Managed and operated by Caltech & MIT with funding from NSF
Goal: Direct observation of gravitational waves
Open a new observational window on the Universe
Livingston, LA
LIGO-G

4. LIGO Scientific Collaboration
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
CSU Fullerton
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
Tsinghua University
Universitat de les Illes Balears
Univ. of Massachusetts Amherst
University of Western Australia
Univ. of Wisconsin-Milwaukee
Washington State University
University of Washington
LIGO Scientific Collaboration
LIGO-G
UCLA Symposium Nov. 2009

5. General relativity – gravitational waves
“Matter tells spacetime how to curve. Spacetime tells matter how to move.” J. A Wheeler
Albert Einstein 1916
GW: oscillating quadrupolar strain in spacetime
Laser Interferometer
LIGO-G
UCLA Symposium Nov. 2009

6. Potential sources Coalescing Binary Systems Burst Sources
Credit: AEI, CCT, LSU
Coalescing Binary Systems
neutron stars
low mass black holes
NS/BS systems
Credit: Chandra X-ray Observatory
Burst Sources
galactic asymmetric core collapse supernovae
cosmic strings
???
Casey Reed, Penn State
Continuous Sources
spinning neutron stars
probe crustal deformations
NASA/WMAP Science Team
Cosmic GW background
stochastic incoherent background
LIGO-G
UCLA Symposium Nov. 2009

7. Capturing the waveform
Sketch:
Kip Thorne
LIGO-G
UCLA Symposium Nov. 2009

8. Detection of gravitational waves
Michelson interferometer
- differential length change sensor
LIGO-G
UCLA Symposium Nov. 2009

9. LIGO detectors Power recycled Michelson interferometer
Laser
4 km-long Fabry-Perot arm cavity
recycling
mirror
test masses
beam splitter
Power recycled
Michelson
interferometer
with Fabry-Perot
arm cavities
signal
LIGO-G
UCLA Symposium Nov. 2009

10. Beam tubes and chambers
1.2 m diameter
LN2 pumps at ends
P < 1e-09 torr
dominated by H2
LIGO-G
UCLA Symposium Nov. 2009

11. Isolated environment for test masses
LIGO-G
UCLA Symposium Nov. 2009

12. Suspended test masses
LIGO-G
UCLA Symposium Nov. 2009

13. Initial LIGO displacement sensitivity
Antenna patterns
NS-NS binary inspiral range ~ 15 Mpc (S/N = 8)
+ pol
S5 science run
11/05-10/07
G pol
avg
LIGO-G
UCLA Symposium Nov. 2009

14. Scientific results of S5 run
No detections (so far) - data still being analyzed
Astrophysical results – upper limits “If LIGO didn’t detect it, then it can’t be bigger than …”
CRAB pulsar – “no more than 4 percent of the energy loss of the pulsar is caused by the emission of gravitational waves.” (ApJL 683, L45)
Gamma ray burst GRB – LIGO “results give an independent way to reject hypothesis of a compact binary progenitor in M31” (ApJ 2008, 681, 1419)
Upper limit on the stochastic gravitational wave background ( v460/n7258/pdf/nature08278.pdf)
Credits for X-ray Image: NASA/CXC/ASU/J. Hester et al.
Credits for Optical Image: NASA/HST/ASU/J. Hester et al.
LIGO-G
UCLA Symposium Nov. 2009

15. What’s next? Advanced LIGO
Quantum noise limited interferometer
Factor of 10 increase in sensitivity
Factor of 1000 increase in event rate
LIGO-G
UCLA Symposium Nov. 2009

16. Laser source: 10 W to 200 W Diode-pumped YAG lasers LIGO-G0901004
UCLA Symposium Nov. 2009

17. Vibration isolation: passive to active
Masses and damped springs
Geophones and accelerometers on payload
Active feedback control – 6 deg. of freedom
LIGO-G
UCLA Symposium Nov. 2009

18. Test mass suspensions Single pendulum
Quadruple pendulum with reaction masses
40 kg test masses
LIGO-G
UCLA Symposium Nov. 2009

19. Time warp – Rm.1763 Boelter Hall
LIGO-G
UCLA Symposium Nov. 2009

20. To Frank ……. thank you.
LIGO-G
UCLA Symposium Nov. 2009