Status of the AURIGA detector at Dec '04

On Dec. 1st 2004 additional mechanical filter have been integrated. As expected, the lowering of the vibration noise in the 10 Hz - 30 Hz  band corresponded to the switching off most of the time of the spurious noise lines which were affecting the gravitational wave sensitive band. In particular, AURIGA  is now stationary and the current typical noise performance is well explained by the predicted noise contributions. The figure below shows the measured one-sided spectral strain noise, in comparison with the predicted noise sources: thermal noise of the mechanical and LC resonators, SQUID back action and additive noises.
We plan to keep AURIGA in continuous observation in the present configuration at 4.5 K until end of February 2005. Then the operation temperature will be lowered to ~ 2 K, in an attempt to further increase the sensitivity.

The additional mechanical filter has been installed between the floor platform and the cryostat. It is made of one stack of highly dissipative elastic material. Some correlation of the AURIGA noise with human activities is still noticeable. As a further improvement, we are preparing a mechanical suspension with a corner frequency close to 1 Hz, based on damped air-springs, to be installed without interruption of the cryogenic run.

For a history of the AURIGA status follow this link.

This page was posted on 22/12/2004


   

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