Dependence of Fission-Fragment Properties On Excitation Energy For Neutron-Rich Actinides

¹ GENP, USC, E-15784 Santiago de Compostela, Spain
² GANIL, CEA/DMS-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 05, France
³ IPN Orsay, Université de paris-Sud, CNRS/IN2P3, F-91406 Orsay Cedex, France
⁴ CIMA, UVigo, E-36310 Vigo, Spain
⁵ LPC Caen, Université de Caen Basse-Normandie-ENSICAEN-CNRS/IN2P3, F-14050 Caen Cedex, France
⁶ CEA Saclay, DMS/IRFU/SPhN, 91191 Gif-sur-Yvette Cedex, France
⁷ Chalmes University of Technology, SE-41296 Göteborg, Sweden

^a e-mail: diego.ramos@usc.es
^b Present address: CEA DAM DIF, F-91297 Arpajon, France
^c Present address: EC-JRC-IRMM, Retieseweg 111, B-2440 Geel, Belgium

Published online: 15 March 2016

Abstract

Experimental access to full isotopic fragment distributions is very important to determine the features of the fission process. However, the isotopic identification of fission fragments has been, in the past, partial and scarce. A solution based on the use of inverse kinematics to study transfer-induced fission of exotic actinides was carried out at GANIL, resulting in the first experiment accessing the full identification of a collection of fissioning systems and their corresponding fission fragment distribution. In these experiments, a ²³⁸U beam at 6.14 AMeV impinged on a carbon target to produce fissioning systems from U to Am by transfer reactions, and Cf by fusion reactions.

Isotopic fission yields of ²⁵⁰Cf, ²⁴⁴Cm, ²⁴⁰Pu, ²³⁹Np and ²³⁸U are presented in this work. With this information, the average number of neutrons as a function of the atomic number of the fragments is calculated, which reflects the impact of nuclear structure around Z=50, N=80 on the production of fission fragments. The characteristics of the Super Long, Standard I, Standard II, and Standard III fission channels were extracted from fits of the fragment yields for different ranges of excitation energy. The position and contribution of the fission channels as function of excitation energy are presented.