High-accuracy determination of the U-238/U-235 fission cross section ratio up to approximate to 1 GeV at n_TOF at CERN
Date Issued
2015-01-01
Author(s)
Paradela, C.
Calviani, M.
Tarr`io, D.
Leal-Cidoncha, E.
Leong, L. S.
Tassan-Got, L.
Le Naour, C.
Duran, I.
Colonna, N.
Audouin, L.
Mastromarco, M.
Lo Meo, S.
Ventura, A.
Aerts, G.
Altstadt, S.
Álvarez, H.
Álvarez-Velarde, F.
Andriamonje, S.
Andrzejewski, J.
Badurek, G.
Barbagallo, M.
Baumann, P.
Bécares, V.
Bev cváv r, F.
Belloni, F.
Berthier, B.
Berthoumieux, E.
Billowes, J.
Boccone, V.
Bosnar, D.
Brugger, M.
Calviño, F.
Cano-Ott, D.
Capote, R.
Carrapic co, C.
Cennini, P.
Cerutti, F.
Chiaveri, E.
Chin, M.
Cortés, G.
Cortés-Giraldo, M. A.
Cosentino, L.
Couture, A.
Cox, J.
David, S.
Diakaki, M.
Dillmann, I.
Domingo-Pardo, C.
Dressler, R.
Dridi, W.
Eleftheriadis, C.
Embid-Segura, M.
Ferrant, L.
Ferrari, A.
Finocchiaro, P.
Fraval, K.
Fujii, K.
Furman, W.
Ganesan, S.
Garc`ia, A. R.
Giubrone, G.
Gómez-Hornillos, M. B.
Gonc calves, I. F.
González-Romero, E.
Goverdovski, A.
Gramegna, F.
Griesmayer, E.
Guerrero, C.
Gunsing, F.
Gurusamy, P.
Haight, R.
Heil, M.
Heinitz, S.
Igashira, M.
Isaev, S.
Jenkins, D. G.
Jericha, E.
Kadi, Y.
Käppeler, F.
Karadimos, D.
Karamanis, D.
Kerveno, M.
Ketlerov, V.
Kivel, N.
Kokkoris, M.
Konovalov, V.
Krtiv cka, M.
Kroll, J.
Lampoudis, C.
Langer, C.
Lederer, C.
Leeb, H.
Losito, R.
Lozano, M.
Manousos, A.
Marganiec, J.
Mart`inez, T.
Marrone, S.
Massimi, C.
Mastinu, P.
Mendoza, E.
Mengoni, A.
Milazzo, P. M.
Mingrone, F.
Mirea, M.
Mondelaers, W.
Moreau, C.
Mosconi, M.
Musumarra, A.
O`Brien, S.
Pancin, J.
Patronis, N.
Pavlik, A.
Pavlopoulos, P.
Perkowski, J.
Perrot, L.
Pigni, M. T.
Plag, R.
Plompen, A.
Plukis, L.
Poch, A.
Pretel, C.
Praena, J.
Quesada, J.
Reifarth, R.
Riego, A.
Roman, F.
Rudolf, G.
Rubbia, C.
Rullhusen, P.
Salgado, J.
Santos, C.
Sarchiapone, L.
Sarmento, R.
Saxena, A.
Schillebeeckx, P.
Schmidt, S.
Schumann, D.
Stephan, C.
Tagliente, G.
Tain, J. L.
Tavora, L.
Terlizzi, R.
Tsinganis, A.
Valenta, S.
Vannini, G.
Variale, V.
Vaz, P.
Versaci, R.
Vermeulen, M. J.
Villamarin, D.
Vincente, M. C.
Vlachoudis, V.
Vlastou, R.
Voss, F.
Wallner, A.
Walter, S.
Ware, T.
Weigand, M.
Weiß, C.
Wiesher, M.
Wisshak, K.
Wright, T.
v Zugec, P.
DOI
10.1103/physrevc.91.024602
Abstract
The U 238 to U 235 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.