Fission-fragment yields and prompt-neutron multiplicity for Coulomb-induced fission of $^{234,235}\mathrm{U}$ and $^{237,238}\mathrm{Np}$

J.-F. Martin (1) , J. Taïeb (1) , G. Boutoux (1) , A. Chatillon (1) , T. Gorbinet (1) , E. Pellereau (1) , L. Audouin (2) , A. Heinz , H. Alvarez-Pol , Y. Ayyad , G. Bélier (1) , J. Benlliure , M. Caamaño , E. Casarejos , D. Cortina-Gil , A. Ebran (1) , F. Farget (3) , B. Fernández-Domínguez , L. Grente (1) , H.T. Johansson , B. Jurado (4) , A. Kelić-Heil , N. Kurz , B. Laurent (1) , C. Nociforo , C. Paradela , S. Pietri , A. Prochazka , J.L. Rodríguez-Sánchez , D. Rossi , H. Simon , L. Tassan-Got (2) , J. Vargas , B. Voss , H. Weick

1 DAM - Direction des Applications Militaires
2 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
3 LPCC - Laboratoire de physique corpusculaire de Caen
4 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

Low-energy fission of ${}^{234,235}\mathrm{U}$ and ${}^{237,238}\mathrm{Np}$ radioactive beams, provided by the Fragment Separator (FRS) of the GSI Helmholtzzentrum für Schwerionenforschung facility (GSI), has been studied using the Reactions with Relativistic Radioactive Beams / Studies on Fission with Aladin (R3B/SOFIA) setup. The latter allows us, on an event-by-event basis, to simultaneously identify, in terms of their mass and atomic numbers, the fissioning nucleus in coincidence with both fission fragments after prompt-neutron emission. This article reports new results on elemental, isotonic, isobaric, and isotopic yields. Moreover, the high accuracy of our data allowed us to study in detail proton even-odd staggering, from elemental yields; neutron excess, from isotopic yields; and total prompt-neutron multiplicity, from the difference of masses of the fissioning nucleus and fission fragments. These results are then compared to previous experimental data in order to probe how these fission observables change as function of the excitation energy and atomic and neutron numbers of the compound nucleus.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

J.-F. Martin, J. Taïeb, G. Boutoux, A. Chatillon, T. Gorbinet, et al.. Fission-fragment yields and prompt-neutron multiplicity for Coulomb-induced fission of $^{234,235}\mathrm{U}$ and $^{237,238}\mathrm{Np}$. Phys.Rev.C, 2021, 104 (4), pp.044602. ⟨10.1103/PhysRevC.104.044602⟩. ⟨hal-03388490⟩