The L-shaped vacuum system for the AEI 10m Prototype consists of three tanks with a diameter of 3m and a height of 3.4m, which are connected by 1.5m diameter beam tubes. The tubes are segmented for ease of installation. Overall, the vacuum system encloses about 100m^3. It is made of about 22t of stainless steel. It is designed as large as possible to fit the existing lab space.
The optical tables are the mechanical interface between the vacuum system and the multiple stage pendulums used to suspend main and ancillary optics of the interferometer. Each table is supported by a Seismic Attenuation System (SAS). The SAS is a six degrees-of-freedom vibration isolator providing the necessary shielding from the ground microseismic noise which is the main environmental source of disturbance for the experiments in the frequency range from 0.1 to 100 Hz.
The Suspension Platform Interferometer measures the relative motion between the seismically isolated optical benches interferometrically. One optical table is installed in each of the three vacuum tanks. The information about the actual table position is used to move the tables back into their initial position by actuators. We aim to achieve a longitudinal displacement of only 100 pm / √Hz at 10 mHz.
The experiments at the AEI Prototype require the relevant optics to be isolated from seismic motion of the ground by about 10 orders of magnitude. Such a powerful isolation can be achieved by the use of multiple cascaded pendulum suspensions, damped at their resonances.
At Fourier frequencies around the resonances of the mirror suspensions a molecular Iodine reference will be used to stabilise the frequency of the 35 W laser system. At higher Fourier frequencies the laser will be stabilised to the length of a suspended 12m triangular ring cavity of finesse F=7300.
The AEI 10m Prototype Interferometer will use a 35W solid-state laser as its light source.
A digital control and data system (CDS) is used for data acquisition and control of the various subsystems. The CDS is based on real-time Linux and EPICS software.