Details

Autor(en) / Beteiligte

• Chebboubi, A.
• Kessedjian, G.
• Serot, O.
• Faust, H.
• Köster, U.
• Litaize, O.
• Sage, C.
• Blanc, A.
• Bernard, D.
• Letourneau, A.
• Materna, T.
• Méplan, O.
• Mutti, P.
• Rapala, M.
• Ramdhane, M.

Titel

Measurements of 233U(nth,f) fission product mass yields with the LOHENGRIN recoil mass spectrometer

Ist Teil von

• The European physical journal. A, Hadrons and nuclei, 2021, Vol.57 (12)

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Numerous measurements of fission product yields were performed since the discovery of the nuclear fission process. However, more precise and reliable fission product yields are requested. Lack of covariance matrices make difficult to use it for specific application purposes such as the propagation uncertainty of decay heat. In this work, we propose to measure independently the fission product mass yields for the whole heavy peak (including the symmetric mass region) for the 233 U ( n th , f ) reaction. Both average values and experimental covariance is provided. The fission product mass yields are measured with the LOHENGRIN recoil mass spectrometer of the ILL using an ionization chamber located at the focal plane. A new procedure of data taking has been developed in order to minimize the biases. Concretely several ionic charges and kinetic energy distributions have been measured for each mass. Particular attention has been considered in the monitoring of the target time evolution. Additional corrections were necessary in the symmetry mass region due to contaminants coming from the LOHENGRIN recoil mass spectrometer. A complex Monte Carlo analysis has been developed in order to better propagate all the uncertainties. The fission product mass yields of the 233 U ( n th , f ) and its associated covariance matrix has been produced. An overall good agreement has been observed with ENDF/B-VIII.0 in contrast with the JEFF-3.3 evaluation. A precision around 2% for the heavy peak has been measured. The experimental covariance matrix was also computed. In the symmetry mass region, two components were observed in the kinetic energy distribution. One of this component was considered as an artifact and was ruled-out.