Demonstration of a switchable damping system to allow low-noise operation of high- Q low-mass suspension systems

Jan-Simon Hennig, Bryan W. Barr, Angus S. Bell, William Cunningham, Stefan L. Danilishin, Peter Dupej, Christian Gräf, James Hough, Sabina H. Huttner, Russell Jones, Sean S. Leavey, Daniela Pascucci (+8 others)
2017 Physical Review D  
Low mass suspension systems with high-Q pendulum stages are used to enable quantum radiation pressure noise limited experiments. Utilising multiple pendulum stages with vertical blade springs and materials with high quality factors provides attenuation of seismic and thermal noise, however damping of these high-Q pendulum systems in multiple degrees of freedom is essential for practical implementation. Viscous damping such as eddy-current damping can be employed but introduces displacement
more » ... from force noise due to thermal fluctuations in the damping system. In this paper we demonstrate a passive damping system with adjustable damping strength as a solution for this problem that can be used for low mass suspension systems without adding additional displacement noise in science mode. We show a reduction of the damping factor by a factor of 8 on a test suspension and provide a general optimisation for this system.
doi:10.1103/physrevd.96.122005 fatcat:on3xfwobvrcqfacqwfpkmoqlvq