Summary: Class.Quantum Grav. 10 (1993) S1854185. Printed in the UK
The Laser InterferometerGravitationalWave Observatory
Stanley E Whitcomb
California Institute of Ethnology, 102-33,Pasadena, CA, 91125,USA
Abstract The LIGO (Laser Interferometer Gravilalional-wave Observatory) project+ is
designed to open a new field of science by detecting and studying the gravitational waves
from astrophysical sources, including neutron stars, black holes,and posribly, supernovae
and the big bang. LIGO will consist of two scientific facilities, each incoprating an
I.-shaped vacuum system with 4-kilometen a m to house sensitive interferometers. A
detector system consists of three interferometers, two at one site and one at the other.
Each interferometer measures the motion of a set of test mmes which are suspended
from seismically isolated suppons and free to move in response to gravitational waves.
Correlations among the three interferometers will be used to eliminate local noise.
LIGO is designed to support a sequence of detector systems of increasing sensilivity
over the next twenty years or longer. In its initial configuration, it will have just one
detector system. However, ils design permits expansion to support three simultaneous
detector systems. The project received funding in 1992 to begin design and construction.
Sites for the two facilities (Hanford, Washington and Ljvingstob Lousiana) have been
selected. Under the present schedule, the facilities will be completed by 1997 and initial