We have calculated the performance of five similar target-moderator-reflector geometries that are reasonably well optimized for long-pulse source applications. For all cases, the moderators are fully coupled; that is, no poisons, decouplers, or liners are used. For each case, the energy- and time-dependent characteristics of the moderator source brightness have been parameteterized using empirical functions. These parameterizations have been made available to users of the Monte Carlo neutron scattering instrument design code MCLIB for use in evaluating the performance of neutron scattering instruments on a long-pulse source.

This paper examines the consequences of adopting a non-moderating reflector and compares its performance to that of beryllium. Reflector studies on a time modulated source have shown lead to be an excellent reflector, maintaining the structure of the long time pulse (500 .mu.s) marginally better than beryllium and with a slightly superior yield. Engineering, fabrication and cost factors as well as improved gamma and fast neutron shielding properties further favour lead as a reflector for these sources. Even for truly pulsed sources which rely primarily on time of flight for energy selection, Monte Carlo studies have shown that a lead reflector maintains an excellent time structure in hydrogenous moderators in the slowing down region. This paper describes the experimental comparison of lead and beryllium reflectors for the case of a pulsed spallation source. The target-moderator-reflector configuration used was a mock-up of the Rutherford Appleton Laboratory's SNS geometry. The experiments were performed in the low current target area of the Los Alamos National Laboratory's spallation source, the WNR. This work was complemented by Monte Carlo calculations using the TIMOC code.

In the present work, the target station of the accelerator-driven neutron source HBS is optimized in comprehensive parameter studies using the Monto-Carlo method. The dependence of the most important performance characteristics of such a system on the external parameters is investigated neglecting technical and mechanical limitations. In this way, qualitative and quantitative statements for all possible configurations and envisaged applications can be derived and should be considered in the detailed planning of such facilities. For this purpose, different scenarios are considered that place completely different requirements on the design of the target station. The central statements derived in this thesis can be transferred to any framework conditions, such as different accelerator energies, so that these results can be used in the development of other neutron sources, which together with the HBS form a European network and provide a prosperous community in neutron science.

This proceedings volume is a collection of papers dealing with the applications of spallation neutron sources to pure science, applied science and defense programs. The topics, ranging from accelerator technology to applications in materials science and neutrino physics, are covered by experts in their respective fields.