This research program was prepared in coordination with the LIGO Scientific Collaboration (LSC), to address the need to understand the thermal background noise of laser interferometric gravitational wave receivers. Its objectives are: to develop a numerical algorithm and software to compute elastic Green's functions for arbitrarily shaped bodies made of anisotropic materials; and to apply the methodology to thermal noise estimations of gravitational wave receivers.

There are several other programs around the world aiming to detect astrophysical gravitational waves by laser interferometry. Their basic idea is to measure the relative displacements of suspended mirrors (or test masses) induced by the passage of gravitational waves using a highly sensitive laser interferometer. Thermally induced surface vibration of the mirror bodies is a major noise source in such a detector. Understanding this important noise source is one of the crucial research areas of the LSC. The ability to calculate the thermal noise for different test mass shapes and sizes should be developed. Dr. Nakagawa has recently obtained a general formula and a computational scheme that enable accurate and efficient computations of thermally induced elastic vibrations of mirror objects. The formula expresses thermal displacement fluctuations in terms of the two key quantities, i.e., complex elastic stiffness and elastic Green's function. While there are several on-going experimental efforts toward determining elastic loss parameters, this focused effort is needed for numerical computation, particularly to deal with (1) arbitrary mirror shapes and (2) anisotropic materials. ***

Agency
National Science Foundation (NSF)
Institute
Division of Physics (PHY)
Application #
9800976
Program Officer
Richard Isaacson
Project Start
Project End
Budget Start
1998-08-15
Budget End
2001-12-31
Support Year
Fiscal Year
1998
Total Cost
$153,200
Indirect Cost
Name
Iowa State University
Department
Type
DUNS #
City
Ames
State
IA
Country
United States
Zip Code
50011