R. Greven, ZEA-1, FZJ). One hard-wired stack with 16 slot-rings (drawing by R. Greven, ZEA-1, FZJ) Simulated electric fields of one excited slot-ring in the middle of the structure at 1 GHz (top: pick-up [...] acceptance electron cooler. CR Stochastic Cooling System For the Collector Ring (CR) of the FAIR project, a 1–2 GHz stochastic cooling system is being developed to provide fast 3D cooling of hot secondary beams [...] following special concepts have been adopted to improve the ratio of Schottky signals to thermal noises: 1) to keep the Pick-Up (PU) electrodes at 30–40 K; 2) to move the electrodes as the beam shrinks; 3) to