On the possibilities of electron cooling for HERA

It is under discussion to operate HERA with heavy ions instead of protons. Because of the heavily increased intrabeam scattering of heavy ions compared to protons, the achievable luminosity is much smaller than desired by the experiments. A way to increase luminosity could be electron cooling of the heavy ion beam. Because of the high electron energy of 180 MeV necessary for cooling heavy ions in HERA the conventional approach using electrostatic DC sources is not possible. Instead an electron storage ring could be used. For this ring there are special requirements like small damping times, emittances and energy spread. The feasibility of such an electron storage ring has been studied, and the results with a possible solution are presented in this paper. Electron cooling of the HERA proton beam is also discussed briefly.