Experimental Progress in Fast Cooling in the ESR

The storage ring ESR is equipped with systems for stochastic cooling and electron cooling. As the ESR is preferentially operated with highly charged ions, the cooling times are in the range of seconds down to some ten milliseconds for cold ion beams in equilibrium with intrabeam scattering. For low beam intensity ordering effects were observed with momentum spreads below 10 -6 and emittances below 10 -12 m. Recent experiments studied electron cooling of an ion beam above transition energy and the use of electron cooling as a pre-cooling method for laser cooling of C 3+ ions.