TH2I3
Fermilab, Batavia, Illinois, USA
The first realization of stochastic cooling in the optical regime was recently achieved at Fermilab’s Integrable Optics Test Accelerator (IOTA) storage ring using the transit-time method of Optical Stochastic Cooling (OSC). OSC uses free-space electromagnetic waves as the signaling medium, pickup and kicker undulators to couple the radiation to the circulating particle beam, and optical amplifiers for signal amplification. Stable cooling was successfully demonstrated in one, two and three dimensions and OSC experiments were performed with a single electron stored in IOTA. The total cooling force in these non-amplified OSC experiments was approximately an order-of-magnitude larger than the natural longitudinal synchrotron-radiation damping. These achievements required precise alignment and femto-second accuracy of the particles with their respective undulator-radiation pulses along with a wide range of technical and diagnostic elements. We describe the integrated OSC system, its performance and comparison to theoretical expectations, and our OSC R&D program that includes advanced concepts in beam cooling and control.
