Annex IV. Applications of neutron beam technology

Neutrons have played an important role in the characterization, development and testing of materials over the past 60 years. Neutrons interact with different materials in very different ways and by careful measurement of the transmitted and scattered neutrons the structure and dynamics of materials can be characterized in a unique way to gather important and sometimes unique information about the materials under study. Neutron beam science took a major step forward with the commissioning of the first purpose built reactors in North America and Europe in the late 1960s. The High Flux Beam Reactor (HFBR) at the Institut Laue-Langevin, Grenoble, France, for example, is an international venture. It has become the benchmark for neutron beam science facilities and has been host to a number of innovations in neutron beam technology leading to the further development of applications of neutron beam technology. Currently there are more than 270 operational research reactors worldwide. Over 100 have a thermal power greater to or equal to 1 MW, and thus have the potential for effective beam line application. Many well known research reactors are overbooked, some are upgraded, new reactors are under construction and with two major new spallation neutron sources under construction the prospect for further neutron beam applications is promising. Nearly sixty years after its birth, the field of neutron beam applications is expanding in both breadth and depth. Modern neutron beam research reactors are purpose designed and built to maximize potential for scientific experiments. There are also a number of smaller university based or national research reactors of low or medium flux and with low or limited applications base. These reactors serve as teaching tools and assist in the maintenance of nuclear expertise. Although it is recognized that some research reactors are under-utilized, there is nonetheless growth in the industry to meet ever increasing worldwide demand for access to neutron beams to address the more difficult challenges of scientific research. This Annex describes the contribution of these interactions to science and technology in the fields of neutron scattering, neutron radiography, neutron activation analysis, and emerging and future trends. New emerging trends are covered by many IAEA technical meetings on neutron beam applications