Reactor Cross-Sections for Fusion
Measurements of Activation Reaction Cross-Sections Important for Fusion Applications.
Tech Area / Field
8 Project completed
Senior Project Manager
Karabashev S G
Khlopin Radium Institute, Russia, St Petersburg
- Institut für Radiumforschung und Kernphysik, Austria, Vienna\nENEA, Italy, Bologna\nArgonne National Laboratory (ANL), USA, IL, Argonne\nPhysikalisch-Technische Bundesanstalt, Germany, Braunschweig\nJAERI, Japan, Tokyo
Project summaryAt the last IAEA Advisory Group Meetings on the Fusion Evaluated Nuclear Data Library it has been stressed that the existing nuclear data files have to be improved to predict more adequately the fusion reactor activation. It was emphasized also that improvements in the FENDL files and reduction of data uncertainties will lead to significant cost savings, for example for the ITER project, by reducing the engineering safety margins related to the uncertainties in the basic nuclear data.
In the last years a substantial progress was made in the measurement of activation cross sections. A very large volume of new data was obtained in JAERI (Japan) where cross sections for most of measurable reactions were determined. In the latest two years cross sections of about 50 reactions have also been measured in KRI (Russia). In the both cases, the measurements were carried out in the strictly fixed and well known conditions using the modern experimental technique and the modern nuclear standards, what provided a high accuracy of results. For each reaction, the data were obtained at 5-8 neutron energy values in interval of 13.3-15.0 MeV. Rather intensive measurements of activation cross sections were curried out in some other research centers last time.
Aiming to concentrate efforts of active investigators on the most important problems, at the IAEA Specialists' Meeting that was held 13-15 November 1993 in Tokai-mura (Japan), the international collaboration was established in which the KRI (Russia) was included. It was suggested to the participants of collaboration, to give a special attention to measurement of the cross sections, the data for which are either absent or unique or scattered too strongly. The most important reactions were specified in two lists: 1) high priority reactions to be measured and 2) reactions needing additional measurements. Besides, it was recommended to develop various experimental methods for a detailed study of the neutron field and extend methods of the induced activity measurement to the X-ray spectroscopy. One of the main objectives of collaboration is to prepare a Handbook containing new recommended data on the activation cross sections important for fusion and applications.
The main content of this Project is the measurement of various reaction cross sections at neutron energy around 14 MeV. The reactions of which cross sections are to be measured can be pided into three groups:
1. Reactions of high priority. They are all very difficult for measurement. Usually, there are no experimental data on them. It is planned to measure 4 of such reactions. Since in this case the reaction products have very long half-lives, the main results for them can be obtained only in the end of the second year of the Project.
2. Reactions of the "list of reactions needing additional measurements". Some data exist but either uncertainties are too large or discrepancies between different results are very significant. 8 reactions of this class will be measured. They are also rather difficult for measurement and require to use separated isotopes, high quality equipment, and efforts of experienced personnel.
3. Usual reactions. As a rule, there is an enormous bulk of experimental data on them. However, the data scattering exceeds remarkably the errors cited by authors not allowing to obtain a good evaluation. About 30 of such reactions will be measured each at seven neutron energy values with paying special attention to all the possible error sources.
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