Quasi-free (p,2p) reactions in inverse kinematics for studying the ﬁssion yield dependence on temperature

Graña Gonzalez, Antia; Johansson, H.T.; Kiselev, O.A.; Rhee, H.-B.; Rossi, D.M.; Törnqvist, H.T.; Rodríguez-Sánchez, J. L.; Benlliure, J.; García-Jiménez, G.; Álvarez-Pol, H.; Cortina-Gil, D.; Atar, L.; Audouin, L.; Authelet, G.; Besteiro, A.; Blanchon, G.; Boretzky, K.; Cabanelas, P.; Casarejos, E.; Cederkall, J.; Chatillon, A.; Corsi, A.; Feijoo, M.; Galaviz, D.; Gasparic, I.; Gernhäuser, R.; Heil, M.; Heinz, A.; Holl, M.; Jenegger, T.; Johansson, H.; Kiselev, O.; Klenze, P.; Knyazev, A.; Körper, D.; Kröll, T.; Liancheng, J.; Lihtar, I.; Litvinov, Y. A.; Löher, B.; Morfouace, P.; Mücher, D.; Murillo-Morales, S.; Obertelli, A.; Panin, V.; Park, J.; Paschalis, S.; Perea, A.; Petri, M.; Pirrone, S.; Ponnath, L.; Revel, A.; Rhee, H. -B.; Rose, L.; Rossi, D.; Russotto, P.; Simon, H.; Stott, A.; Sun, Y.; Sürder, C.; Taieb, J.; Taniuchi, R.; Tengblad, O.; Törnqvist, H. T.; Velardita, S.; Vesic, J.; Voss, B.; on behalf of the R3B Collaboration,

doi:10.22323/1.419.0017

Abstract

Despite the recent experimental and theoretical progress in the investigation of the nuclear ﬁssion process, a complete description still represents a challenge in nuclear physics because it is
a very complex dynamical process, whose description involves the coupling between intrinsic and
collective degrees of freedom, as well as diﬀerent quantum-mechanical phenomena. To improve on
the existing data on nuclear ﬁssion, we produce ﬁssion reactions of heavy nuclei in inverse kinematics
by using quasi-free (p,2p) scattering, which induce ﬁssion through particle-hole excitations that
can range from few to ten’s of MeV. The measurement of the four-momenta of the two outgoing
protons allows to reconstruct the excitation energy of the ﬁssioning compound nucleus and therefore
to study the evolution of the ﬁssion yields with temperature. The realization of this kind of
experiment requires a complex experimental setup, providing full isotopic identiﬁcation of both
ﬁssion fragments and an accurate measurement of the momenta of the two outgoing protons. This
was realized recently at the GSI/FAIR facility and here some preliminary results are presented.