Application of the Optical Stochastic Cooling Mechanism to Electron-Beam Shaping in Storage Rings

Optical Stochastic Cooling (OSC), the extension of microwave stochastic cooling (MSC) to optical frequencies is a phase-space-cooling technique with a cooling time orders of magnitude faster than the MSC. OSC relies on encoding particle information on an optical signal, amplifying and manipulating this signal before coupling it back on the beam to apply a corrective kick. Nominally, the optical system and amplifier are designed to apply a corrective kick which, averaged over many turns, stochastically cools the beam. In this paper, we show that the technique can also be used to control the beam distribution. We specifically suggest and simulate two potential methods for shaping the longitudinal phase-space (LPS) of a circulating beam using the OSC mechanism. The first technique modulates the amplification of the optical radiation in a turn-by-turn fashion so as to resonantly reduce energy offset thereby producing ultra-low energy spread beams. The second method non-uniformly amplifies longitudinal sections of the optical-radiation pulse to target cooling within specific regions of the beam. Using such an approach we demonstrate the generation of beams consisting of micro-bunches with tunable separation. The proposed techniques are general phase space manipulations and could be implemented in various ways to enable full spatiotemporal control of circulat-ina beams in storage rings.