LIGO Document P1100003-v1
- At present a 10m prototype interferometer facility is being set up at the AEI Hannover. One unique feature of the prototype will be the suspension platform interferometer (SPI). The purpose of the SPI is to monitor and stabilise the relative motion between three seismically isolated optical tables. The in-vacuum tables are suspended in an L-shaped configuration with an arm length of 11.65 m. The design goal of the SPI is to stabilise longitudinal differential displacements to a level of 100 pm/sqrt(Hz)
between 10mHz and 100 Hz and relative angular noise of 10 nrad/sqrt(Hz) in the same frequency band. This paper covers the design aspects of the SPI, e.g. cross-coupling
between the different degrees of freedom and fibre pointing noise are investigated. A simulation is presented which shows that with the optical design of the SPI all degrees
of table motion can be arranged to be fully decoupled. Furthermore, a proof of principle test of the chosen technique is shown.
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