Advanced target concepts for production of radioactive ions and neutrino beams

The 1-20 MW of proton beam power which modern accelerator technology put at our disposal for production of intense secondary beams presents a major technically challenge to the production targets. A conceptual design is presented for a high-power pion production target and collection system, which was originally suggested to be used as the source for the proposed CERN muon-neutrino factory. It will be shown that the major parts of this target could also serve as an efficient spallation neutron source for production of 6He and fission products in the two-step converter-target concept. The heart of the system consists of a free surface Mercury jet with a high axial velocity, which allows the heat to be carried away efficiently from the production region. For the neutrino factory the secondary pions are collected and injected into the pion decay-channel by means of a magnetic horn. For the radioactive ion-beam facility the Hg-jet is surrounded by the high-temperature ISOL production-target. The suggested mechanical layout and technical parameters of the Hg-jet, ISOL target, horn and cooling system are discussed. The critical issues are identified and a description of the R&D program designed to provide experimental proof of the principle as well as providing engineering parameters is given.