Summary of third workshop on materials science and technology for the spallation neutron source at KEK, March 2002

The third workshop on the Materials Science and Technology for Spallation Neutron Source was held on 14–15 March, 2002 at KEK to discuss the present status and problems concerning the material issues for the spallation neutron source designs and associated R&D. There were 62 in attendance. The following six topics were energetically discussed: general presentations, radiation damage, solid target, cladding techniques, corrosion tests and accelerator-driven systems. Conclusions were reached in several areas: the basic technology of solid targets, including a Ta-clad tungsten block with the HIP method might be well-established, but irradiation and fatigue data are not yet sufficient. Liquid-target technology seems to have several problems: the urgent problem of mercury targets for neutron-scattering facilities is pitting by pressure waves induced by pulsed protons. The PIE of the STIP experiments is expected to prove the irradiation data. Problems of materials and coolant under irradiation, such as IASCC, should be investigated with the STIP and ion irradiation. Further, R&D for a lead–bismuth target is needed to design an ADS.