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The Latest on LASTI

The Latest on LASTI

- Contributed by Rich Mittleman and David Shoemaker

This has been a busy few months for the LIGO Advanced System Test Interferometer (LASTI) at MIT, as we complete installation of the mechanical infrastructure. A custom, combination clean room and work mezzanine around the BSC (Test Mass) vacuum chamber was designed, fabricated and installed. This provides a safe and spacious environment from which to install the Advanced LIGO seismic isolation and suspension systems. These two will be installed as a "cartridge"--the suspensions will be mounted on the isolation system outside of the vacuum system to ease access, and then lifted together into the Test Mass vacuum chamber. The photo below shows this cleanroom. It also shows the low ceiling height (which is a nuisance), and the nifty two-lift bridge crane (which is a boon!) used to lift the cover off the chamber and to tuck it up into the rafters for maximum clearance of the future contents of the chamber.

Clean room/Work mezzanine around the test mass vacuum chamber.

Once the platform was installed, we opened our Test Mass vacuum chamber, and our local crowd plus Special Hanford Guest Stars Hugh Radkins and Corey Gray worked diligently to get the "Blue Piers" placed, and to bring in the horizontal support tubes and bellows. The tight working quarters (compared with the LIGO sites) leads to a need for some imaginative contortions, but all's well that ends well, and all the pieces are in place.

Putting the lid on.

The photo above shows the cover floating from the crane, with the protective cover on for cleanliness (it is on its way back on after having "relaxed" on the floor for a week). There is a little excitement in using the crane--between two sections of the bridge, there is a short distance with no electricity, so one must have a certain amount of momentum to carry the load beyond that point. Rich Mittleman at the controls is just guiding it past this delicate point.

Pumpdown of the vacuum chamber.

Lastly comes the pumpdown, shown above. Here Mike Zucker is seen supplicating to the gods of vacuum that all leaks be closed. We had a few "dinged" flanges which required some spit and polish to close up, and as we go to press we are still leak checking. Stay tuned...