Cryogenic Interferometry and Suspension Development for Future Gravitational Wave Detectors.

Future gravitational wave detectors such as the Einstein Telescope will use cryogenic cooling of the suspended test-mass mirrors to reduce the impact of thermal noise of the detector sensitivity. A methodology that combines cryogenic materials studies, monolithic suspensions assembly, cryogenic cooling, and seismic isolation is needed to prove the viability of this critical technology for future detectors. Meaning this research is extremely timely, novel, and will have a strong impact on the research field and the final design of the Einstein Telescope. In this work the thermal and mechanical properties of cryogenic silicon and sapphire fibres will be investigated as candidate materials for the Glasgow prototype interferometer using cryogenically cooled monolithic suspended optics. This would be the first demonstration of a monolithical suspended and cryogenically cooled laser interferometer, a key technology demonstration needed for future gravitational wave detectors. The project will develop experimental techniques for characterisation of thermal conductivity, mechanical strength and loss, adapting experiments to low cryogenic temperatures, and performing new characterisation of samples produced with novel fabrication and bonding techniques.