Summary of emittance control in the SLC linac

Abstract

The Stanford Linear Collider (SLC) electron-positron collider requires micron-size beams at the collision point in order to make maximum luminosity, which requires small beam emittances. These small emittances must be produced in the damping rings and accelerated down the linac without significant enlargement. The authors describe measurements of the beam emittance at various locations along the beam's trajectory and the techniques used to diagnose and correct errors. Measurements of the emittances of the beams exiting the damping rings as a function of the storage time show that the injected emittances are about three times larger than the design. Injection oscillations and betatron mismatches into the damping rings are the suspected causes of this enlargement. >