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A large-scale, high-efficiency and low-cost platform for structural genomics studies". Acta Crystallogr D Biol Crystallogr. (2006) 62 (8):843-51

A new neutron powder diffractometer, SPICA, at the ninth beamline has been constructed for the study of materials under special environments at J-PARC. We have made shielding design for SPICA with the Monte Carlo transport code system, PHITS, considering shield optimization to reduce amount of shields and to simplify shield configuration. At the first time, a reference design of the optimized multilayer shield was made using conventional shielding materials such as iron, concrete, polyethylene and boric acid resin. Then, novel monolayer shield design has been performed to give equivalent or lower radiation dose rates than those of the reference design by using the new neutron shielding concrete which contains colemanite and peridotite used as a aggregate of concrete. Overall shield thickness saving was also attained in the main shields for the neutron scattering room.

No abstract