Gravitational waves offer an unprecedented opportunity to see the universe from a new perspective, providing access to astrophysical insights that are available in no other way. Advanced LIGO?s (AdvLIGO) goal is to pioneer a new field of gravitational-wave astronomy. AdvLIGO is an upgrade to the initial Laser Interferometer Gravitational-wave Observatory (LIGO) detectors and will take place over FY 2008 ? FY 2015. LIGO was conceived as an infrastructure to support a series of improving instruments, and AdvLIGO will re-use the civil construction, vacuum equipment, and environmental monitoring system while replacing the detector components at the Hanford, WA and Livingston, LA observatory sites. The AdvLIGO design is the product of the LIGO Laboratory research and development program and the focused effort of the LIGO Scientific Collaboration, informed by the experience from initial LIGO. The complete AdvLIGO detector consists of three interferometers: one 4-km instrument at the Livingston site, and two 4-km instruments at the Hanford site. The instruments are taken through integration and test, with the prime project objective met when each interferometer is capable of being brought reliably to an operational state (?locking?) for multi-hour periods. The Caltech-MIT LIGO Laboratory, with Caltech as the responsible fiduciary institution, will carry out the project. Other members of the LIGO Scientific Collaboration (LSC), on subcontract from Caltech/MIT, will participate in all phases of the effort. The UK (Science and Technology Facilities Council funding) and Germany (Max Planck Institute funding) are contributing significant capital equipment and manpower, complementing the NSF funding.
Intellectual merit: AdvLIGO will increase the sensitivity over initial LIGO by more than a factor of 10, and thus the volume searched and potential rate of signals by a factor of more than 1000. The available bandwidth is larger, and the frequency response tunable, to address a range of astrophysical sources of gravitational waves. It is anticipated from current astrophysical knowledge that there will be frequent observations of gravitational waves, allowing a broad exploration of heretofore inaccessible astrophysics, cosmology, and relativity. Tests of general relativity in the strong field region near black holes will provide data that will help advance numerical relativity and gravitational theory. AdvLIGO will observe in coordination with other gravitational-wave detectors. The resulting observations will complement those from existing photon and neutrino observatories, increasing their reach, and giving new qualitative and quantitative understanding of the cosmos.
Broader impacts: AdvLIGO is the long-term focus of the entire LSC, including 46 institutions and roughly 600 members globally. In this light, implementing AdvLIGO will directly support a scientific community which came into being due to LIGO. In addition, LSC education and outreach activities of member institutions (including the LIGO Laboratory?s very active program) will be greatly enhanced by the onset of gravitational-wave astronomy -- and the new eye on the universe, achieved by pushing instrument science to fundamental limits, will inspire a generation of young people to consider the excitement of science and engineering as a career.
