Laboratory Technology Development of the Technology for Intermediate Energy Electron Cooling

Low energy (5300 keV) electron cooling is a well-developed technology. In the past 5 years, 8 systems have been commissioned in the U.S. (I), Europe (6)) and Japan (1). We believe that intermediate-energy electron cooling, in the electron energy range of 110 MeV for cooling 2-20 GeV/nucleon ion beams, would be exploited on a similar scale if the technology were available. Above electron energies of about 500 keV, the traditional approach of using a Cockcroft-Walton power supply and a magnetically-confined electron beam becomes impractical. Instead, it has been proposed to use non-magnetically confined electron beams generated and collected in the terminal of a Pelletron accelerator for beam energies in the range from 1 to 10 MeV for cooling 2 to 20-GeV proton beams.' Although this technology has been partially developed, an order of magnitude improvement in the performance demonstrated to date is needed to exploit electron cooling at higher energies. The COLDER (Collaboration Of Laboratories Developing Electron Recirculation) group is assembling a proof-of-principle system to demonstrate this technology at the National Electrostatics Corporation.