Scientific officer, Bhabha Atomic Research Center, Trombay, Bombay,
Head, Bhabha Atomic Research Center, Trombay, Bombay,
Pages: 10 Published: Jan 1990
The spallation neutron source (SNS) is considered an excellent tool for simulating the neutron radiation environment of the first wall of future fusion reactors and the test materials used for it. Because of the presence of a high-energy tail in the spallation neutron spectrum, some new transmutation products are generated that are not produced by fusion spectra. To establish the technical feasibility of SNS as a tool for such a simulation, one needs a detailed study of the buildup and decay characteristics of transmutation nuclides. One also needs to show that the buildup of the “undesired” transmutation products is small enough so that they do not influence the mechanical properties of the test samples towards one end of the material's life. The effect of the high energy component of the SNS neutron spectrum on hydrogen and helium generation also needs to be studied.
We have discussed in this paper a method of performing activation calculations for samples irradiated by the SNS. We have shown that the hydrogen-to-helium ratio for iron (Fe) samples irradiated in SNS is comparable to that in the fusion reactor's first wall.
We have carried out a study of the buildup and decay characteristics of the transmutation product. We present in this paper some of early results of this study. A more detailed study is in progress. The paper limits itself to the mechanism of buildup of these transmutation products, and no attempt is made to discuss the metallurgical implication of this buildup.
We have also discussed in this paper an evaluation technique for producing a transmutation nuclide cross-sectional library for up to 600 MeV of neutron and proton energy and have provided some representative results from this evaluated library.
transmutation product, fusion materials, simulation studies, spallation, activity, hydrogen, helium, cross section
Paper ID: STP49479S