Inventors

Yutaka Yamagata, Katsuya Hirota (Advanced Manufacturing Metrology Laboratory),
Jung-Myoung Ju (Ultra High Precision Fabrication Team)

Background

In recent years, there have been attempts to develop small neutron sources in order to explore the use of neutron beams for scientific and industrial applications. The technology presented here generates neutrons with a small particle beam accelerator, making possible the efficient use of neutrons in combination with neutron optical elements. Several elemental technologies are necessary for the development of small neutron sources. The development of a neutron target to generate the neutrons is one of the most important of these technologies.

Summary

The low-energy proton beams and deuteron beams used in small neutron sources destroy the metallic plate as a result of hydrogen embrittlement when they stop within the beryllium layer. The inventers therefore precisely calculated the penetration range of charged particles inside the target and adjusted the thickness of the beryllium layer so that the proton beam would stop downstream of it. In addition, they solved the problems of heat removal and hydrogen embrittlement simultaneously and also successfully improved the safety during maintenance with low activation by selecting a metal that had high hydrogen diffusibility, good thermal conductivity, and a relatively low long-term activation from neutron irradiation to be the backing plate.

Merits

• Extended life of neutron generation target
• Simplified maintenance thanks to low long-term activation
• Reduction in running cost thanks to extended life

Applications

• Neutron generation target for small neutron sources

References

• 1.Japanese patent No.5888760