Beam feedback electronics for the spear storage ring

Abstract

The two beams of the 2 GeV Stanford electron-positron storage ring can exhibit, under certain modes of operation, coherent oscillations which have a rate of growth proportional to the beam current.Since this rate is much slower than the machine revolution tiequency, it is possible to produce damping by means of negative feedback, the beam itself being part of the feedback loop. Three systems have been built, two for the damping of transverse oscillations at the betatron frequency, and one for the damping of longitudinal oscillations at the synchrotron frequency. The electronics for these systems require wide band high power amplifiers and nanosecond circuitry.