Speaker
Description
The necessary improvement of evaluated nuclear data for nuclear applications development is possible through new and high-quality experimental measurements, often combined with appropriate nuclear-reaction modelling. In particular, improving inelastic cross-section evaluations requires new and high-quality data.
Our group at CNRS-IPHC developed an experimental program to measure (n, n’ gamma) cross-sections using prompt gamma-ray spectroscopy and neutron energy determination by time-of-flight [1-3]. To extract, from these partial data, the total inelastic cross-section, we rely on theoretical model as well as nuclear structure data such as gamma ray emission probabilities.
This structure information, tabulated in databases such as ENSDF, comes with uncertainty (although, in some cases, the uncertainty may not even be known or quoted in the tables). This directly affects the precision of our results, regardless of how good the measurement is.
To reach the extra precision needed for evaluation, we want to lower the uncertainties on nuclear structure data, so that it reflects directly on the precision of experimentally derived cross-sections.
In the talk, we will present the issue of limited precision structure data and its impact on nuclear reaction data quality in the case of neutron inelastic scattering measurements. We will discuss how to foresee and mitigate the issue. Finally, we will list key nuclear structure data that are needed to directly improve experimentally extracted cross-section data.
- [1] “What can we learn from (n, x n γ) cross sections about reaction mechanism and nuclear structure ?”, by Kerveno, Maëlle and Dupuis, Marc and Borcea, Catalin and Boromiza, Marian and Capote, Roberto and Dessagne, Philippe and Henning, Greg andHilaire, Stéphane and Kawano, Toshihiko and Negret, Alexandra and Nyman, Markus and Olacel, Adina and Party, Eliot and Plompen, Arjan and Romain, Pascal and Sin, Mihaela. ND 2019 : International Conference on Nuclear Data for Science and Technology (2019). 10.1051/epjconf/202023901023 https://hal.archives-ouvertes.fr/hal-02957494
- [2] “How to produce accurate inelastic cross sections from an indirect measurement method ?”, by Kerveno, Maëlle and Henning, Greg and Borcea, Catalin and Dessagne, Philippe and Dupuis, Marc and Hilaire, Stéphane and Negret, Alexandru and Nyman, Markus and Olacel, Adina and Party, Eliot and Plompen, Arjan in EPJ N - Nuclear Sciences & Technologies 4, (2018). 10.1051/epjn/2018020 https://hal.archives-ouvertes.fr/hal-02109918
- [3] “From γ emissions to (n,xn) cross sections of interest : The role of GAINS and GRAPhEME in nuclear reaction modeling”, by Kerveno, M. and Bacquias, A. and Borcea, C. and Dessagne, Ph. and Henning, G. and Mihailescu, C. and Negret, A. and Nyman, M. and Olacel, A. and Plompen, M. and Rouki, C. and Rudolf, G. and Thiry, C. in European Physical Journal A 51, 12 (2015). 10.1140/epja/i2015-15167-y https://hal.archives-ouvertes.fr/hal-02154831
