High-accuracy determination of the 238U/235U fission cross section ratio up to ~1 GeV at n_TOF at CERN
2015 (English)In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 91, 024602- p.Article in journal (Refereed) Published
The U238 to U235 fission cross section ratio has been determined at n_TOF up to ≈1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3–4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n_TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to ≈1 GeV.
Place, publisher, year, edition, pages
2015. Vol. 91, 024602- p.
IdentifiersURN: urn:nbn:se:uu:diva-245577DOI: 10.1103/PhysRevC.91.024602ISI: 000350174000004OAI: oai:DiVA.org:uu-245577DiVA: diva2:791231