Advanced spallation sources; scientific opportunities and technical feasibility

In order to meet with the growing demands both for neutron scattering facilities as such and for more sophisticated experiments to obtain more detailed and clear cut information, a new generation of neutron sources is necessary which allows optimum use of the neutrons produced to give enough intensity for very high resolution work as well as for the investigation of phenomena with very low signal rates. Spallation neutron sources with a short primary neutron pulse and flexibly designed fast as well as coupled moderators together with a variety of imminent new phase space handling techniques have a prospect of satisfying the scientific needs also in the future. They are technically feasible both on the part of accelerators, which have not been dealt with in this paper and on the part of target systems, where new design routes can be followed. 9 refs., 2 figs., 1 tab