Suspension and Suspension Noise for LIGO Test MassesDescription:The Laser Interferometer Gravitational-Wave Observatory (LIGO) project is a pioneering effort to design and construct a unique scientific facility–a gravitational-wave observatory–that will open a new observational window on the universe. A key part of the LIGO project is a collaborative program of experimental research, by Vladimir Braginsky's Moscow University research group, in LIGO, with special focus on issues relevant to "advanced" interferometers that would operate in the LIGO vacuum system after the first interferometers have completed their studies. Most of the research will focus on suspension systems for the interferometers' test masses. Several versions of the suspension system will be developed and tested in Moscow. The key goals of this research will be: to achieve the highest possible quality factors Q for the suspensions' pendulum modes and violin modes (Q's greater than 108 are expected) with test masses of 1 to 2kg, and thereby to reduce the thermal noise that the suspension introduces into LIGO's gravity-wave searches; to investigate the level of excess noise (non-Gaussian noise of non-thermal origin) in several versions of the suspension; to develop theoretical models to explain the observed excess noise, and to compare those models with the experimental measurements. The Moscow group will transfer to the Caltech/MIT LIGO team the know-how, techniques, and technology for suspension systems that they develop. In addition, they will make recommendations to the U.S. LIGO team about the design of test-mass systems for advanced interferometers, and will provide estimates of the thermal noise that recommended suspensions would introduce into the interferometers. The Moscow group will also provide ongoing advice to the LIGO team about various aspects of the team's interferometer R&D program, including the R&D for the first LIGO interferometers. In conjunction with this experimental work, the Moscow group–collaborating with members of Kip Thorne's Caltech group and possibly with members of the LIGO team–will analyze various "Quantum Non-demolition" (QND) readout systems for very advanced LIGO interferometers. These QND readout systems will have the goal of beating the "standard quantum limit" for interferometer sensitivity.Benefits:The key goals of this research will be to achieve the highest possible quality factors Q for the suspensions' pendulum modes and violin modes (Q's greater than 108 are expected) with test masses of 1 to 2kg, and thereby to reduce the thermal noise that the suspension introduces into LIGO's gravity-wave searches; to investigate the level of excess noise (non-Gaussian noise of non-thermal origin) in several versions of the suspension; to develop theoretical models to explain the observed excess noise, and compare those models with the experimental measurements.Russian InstitutionsName: Institute for High-performance Computing and Data Bases (IHPCDB) US InstitutionsName: National Center for Supercomputing Applications - NCSA |
