Sannibale, V.Abbott, B.Aso, Y.Boschi, V.Coyne, D.DeSalvo, R.Marka, S.Ottaway, D.Stochino, A.2011-12-092011-12-092008Journal of Physics : Conference Series, 2008; 122:1-61742-65881742-6596http://hdl.handle.net/2440/68697Conference proceedings details: Proceedings of the 7th Edoardo Amaldi Conference on Gravitational Waves (Amaldi7), Sydney Convention and Exhibition Centre, Darling Harbour, Sydney, Australia, 8–14 July 2007 / Susan M Scott and David E McClelland (eds.)The Horizontal Access Module Seismic Attenuation System (HAM-SAS) is a mechanical device expressly designed to isolate a multipurpose optical table and fit in the tight space of the LIGO HAM Ultra-High-Vacuum chamber. Seismic attenuation in the detectors' sensitivity frequency band is achieved with state of the art passive mechanical attenuators. These devices should provide an attenuation factor of about 70dB above 10Hz at the suspension point of the Advanced LIGO triple pendulum suspension. Automatic control techniques are used to position the optical table and damp rigid body modes. Here, we report the main results obtained from the full scale prototype installed at the MIT LIGO Advanced System Test Interferometer (LASTI) facility. Seismic attenuation performance, control strategies, improvements and limitations are also discussed.en© 2008 IOP Publishing LtdJournal article002011306510.1088/1742-6596/122/1/0120102-s2.0-6564910226027583Ottaway, D. [0000-0001-6794-1591]