Speaker
Description
Vertical seismic attenuation in gravitational wave detectors relies on materials that show very small creep but their dissipative properties are crucial for assessing the vertical thermal noise that they generate. Due to Earth curvature, vertical thermal noise is projected onto the interferometer plane by a non-negligible vertical-to-horizontal coupling factor, making it a limiting noise source. Maraging steel has been used for almost thirty years, but systematic data about dissipation at low frequency have not been collected yet. We present measurements at room temperature of mechanical oscillation damping in a purpose-built maraging steel cantilever spring at low frequency under different stress conditions. These results are relevant for assessing the impact of suspension thermal noise on the sensitivity of the ET-LF detector.