A laser alignment system for low beta quadrupoles

The positions of the low beta quadrupoles in the B0 area of the Fermilab Tevatron were monitored using a laser-based system. Two identical systems were used on either side of the collision point. The essential components of each system included a 2 mWatt helium neon laser, a set of lenses which could be remotely flipped into the laser beam, and a four quadrant silicon photocell detector. A computer system took the data remotely and stored the data in files for chronological comparisons. Mainly due to drifts in the laser, the accuracy of the system was 0.5 mm, but this was sufficient to check for long-term settling of the area around the collision pit.<>