The 100 MeV preinjector for the Trieste synchrotron

A 100-MeV electron linac, used as a preinjector for a 2-GeV booster synchrotron, is described. Three operating modes are possible: a single-bunch mode with one booster RF-bucket (500 MHz) filled, a multibunch mode with 5 to 150 buckets filled, and a free electron laser mode which provides a long pulse beam with energy ranging from 30 to 75 MeV. The linac includes a triode gun and subharmonic chopper/prebuncher cavities, followed by a five-band buncher and two accelerating structures. Specifications on the beam current, emittance, and energy spread require special care in the choice of the operating parameters. This project is a step in the design of compact injectors for light sources, such as those being developed for the European Synchrotron Radiation Source and those for HELIOS, a synchrotron light source dedicated to microlithography.<>