Author: Matthew Pietryka

Institution: SLAC Stanford Linear Accelerator Center, Stanford University

Co-Author: M. Gaydosh, T. King

Title of Presentation:

Re-visiting SPEAR after 25 Years


The SPEAR ring stored its first colliding beams 25 years ago. It is now the heart of the Stanford Synchrotron Radiation Lab. The original alignment scheme used floor monuments which were adjusted to their ideal positions and standard offsets measured with optical tooling transits. In 1995 the entire ring and beamline complex was re-surveyed and re-aligned using modern technology. Ground motion had distorted the ring geometry dramatically, and 10mm longitudinal dipole positioning errors were discovered. The beamline areas were traversed for the first time ever. The task of restoring the design orbit and maintaining the signals to all experiments will be presented.