Next-Generation Neutron Sources

This article gives an overview of current neutron-scattering facilities and illustrates the capabilities of third-generation sources that are now under development.The new science that is driving this development has been illustrated in the articles in this issue of MRS Bulletin and in a previous issue published in 1999 [MRS Bull. 24 (12) (1999) p. 14].The scale of these facilities is such that only three of them are envisaged worldwide, in the Asia Pacific region, Europe, and America.Two construction projects, the spallation neutron sources in the United States (SNS) and in Japan (J-PARC), are now well under way, while the European proposal for a spallation source (ESS) is still awaiting a decision to start construction.