Multilayer test masses to enhance the collapse noise

Thermoelastic noise and homogeneous thermal noise in finite sized gravitational-wave test masses

An analysis is given of thermoelastic noise ~thermal noise due to thermoelastic dissipation! in finite sized test masses of laser interferometer gravitational-wave detectors. Finite-size effects increase the thermoelastic noise by a modest amount; for example, for the sapphire test masses tentatively planned for LIGO-II and plausible beam-spot radii, the increase is &10 percent. As a side issue...

Noise Robustness in Multilayer Neural

Internal thermal noise in the LIGO test masses : a direct approach

The internal thermal noise in LIGO’s test masses is analyzed by a new technique, a direct application of the Fluctuation-Dissipation Theorem to LIGO’s readout observable, x(t) =(longitudinal position of test-mass face, weighted by laser beam’s Gaussian profile). Previous analyses, which relied on a normal-mode decomposition of the test-mass motion, were valid only if the dissipation is uniforma...

Brownian thermal noise in multilayer coated mirrors

We analyze the Brownian thermal noise of a multilayer dielectric coating used in high-precision optical measurements, including interferometric gravitational-wave detectors. We assume the coating material to be isotropic, and therefore study thermal noises arising from shear and bulk losses of the coating materials. We show that coating noise arises not only from layer thickness fluctuations, b...

Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder.

We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge contro...