Speaker
Munetake Otsuka
Description
Improving thermal noise in the cryogenic sapphire suspension is one of the key factors for further enhancing the sensitivity of KAGRA.
In this presentation, the contribution of thermal noise from each component of the cryogenic sapphire suspension to the KAGRA sensitivity is first described.
Efforts to reduce thermal noise in the cryogenic sapphire suspension are then presented, focusing on improvements in the quality factors (Q factors) of sapphire fibers and blade springs. For sapphire fibers, improvements through bonding, polishing, and Sumiceram treatment, among others, are presented, while for blade springs, optimization of their geometry is discussed.
Author
Munetake Otsuka
Co-author
on behalf of KAGRA Collaboration