Work on the Laser Interferometer Gravitational-wave Observatory (LIGO) continues to progress smoothly. The bake out of the beamtubes at the Hanford site was concluded in May, completing the facilities and infrastructure work there. The bakeout equipment have now been shipped to the Livingston site, and the bakeout of the first beamtube module should start within weeks.
The main activities have now shifted to detector installation at both sites. At Hanford, the seismic isolation installation for the first interferometer is nearly complete, and over half of the optics have been installed in the vacuum chambers. The prestabilized laser has been installed and under test for several months. A major current focus is locking the laser to the mode cleaner, the first step in integrating and commisioning the first detector. At Livingston, the first installations are the seismic isolation system and the prestabilized laser; both are well underway.
At the most recent meeting of the LIGO Scientific Collaoration, held at Stanford in July, the main focus was initial discussion and planning for a improved detectors to replace the current ones starting in 2005. Although there is significant R&D to completely define these detectors, it is clear that significant sensitivity improvements are possible.
Progress on LIGO (including pictures of the installation activities) can be followed in our (nearly) monthly newsletters accessible through our website (http//:www.ligo.caltech.edu).