Wake Field Work at DESY

At DESY, we are investigating the applicability of the "Wake Field Transformer" concept [1] for high gradient acceleration of particles. In this paper we will focus on the experiment which is under construction. We have built a 8 MeV high current linac for generation of a hollow driving beam of 1 ¿Coulomb charge. The hollow beam gun came into operation in March 1985 and is laser driven with a tungsten (or tantalum) cathode. This new type of gun does not need extremely high vacuum and is very reliable. The linac will come into operation in May. By the end of 1985, we hope to have first results from the Wake Field Transformer operation. All parts including the gun, linac cavities, solenoid coils and the transformer have already been manufactured.