Timing and RE synchronization for filling PEP/SPEAR with the SLC damping rings

An innovative timing and RF synchronization system has been built and commissioned. The system allows the direct injection of 1-mm e ⁺ or e^- bunches from the SLC (Stanford Linear Collider) damping rings (DRs) (v_RF=714 MHz) into the storage rings PEP (v _RF=353 MHz) and SPEAR (v_RF=358 MHz). The required relative stability of these oscillators is 10^-9 since the beams may be stored in each DR for up to 0.2 s (during which no timing correction is made), and must be delivered within a 0.5 ns window. Stability has been obtained by phase-locking the storage ring RF to the Linac-DR master oscillator. In order to obtain bunched beams for acceleration in the Linac 10.5 cm RF structure while maintaining the storage ring timing requirements, the subharmonic buncher and DR RF are phase-shifted using GaAs digital circuitry. The phase-locked loops, the RF distribution system, the S-band resettable dividers, and the interpulse timing system components used in this project, are described