High precision measurements on fission-fragment de-excitation. (November 2017)

• Record Type: Journal Article
• Authors: Oberstedt, Stephan; Gatera, Angélique; Geerts, Wouter; Göök, Alf; Hambsch, Franz-Josef; Vidali, Marzio; Oberstedt, Andreas
• Is Part Of: Radiation physics and chemistry. Volume 140(2017)
• Page Start: 458
• Page End: 462
• Publication Date: 2017-11
• Subjects: Nuclear fission -- Nuclear de-excitation -- Fission γ rays -- Prompt fission neutrons -- Nuclear applications; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2017.02.042
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: In recent years nuclear fission has gained renewed interest both from the nuclear energy community and in basic science. The first, represented by the OECD Nuclear Energy Agency, expressed the need for more accurate fission cross-section and fragment yield data for safety assessments of Generation IV reactor systems. In basic science modelling made much progress in describing the de-excitation mechanism of neutron-rich isotopes, e.g. produced in nuclear fission. Benchmarking the different models require a precise experimental data on prompt fission neutron and γ -ray emission, e.g. multiplicity, average energy per particle and total dissipated energy per fission, preferably as function of fission-fragment mass and total kinetic energy. A collaboration of scientists from JRC Geel (formerly known as JRC IRMM) and other institutes took the lead in establishing a dedicated measurement programme on prompt fission neutron and γ -ray characteristics, which has triggered even more measurement activities around the world. This contribution presents new advanced instrumentation and methodology we use to generate high-precision spectral data and will give a flavour of future data needs and opportunities. Abstract : Highlights: Position-sensitive Frisch-grid ionization chamber to determine the emission angle of prompt fission neutrons with respect to the fission axis. Implementation of lanthanide-halide detectors to measure prompt fission gamma-ray spectral characteristics. Efficient separation of prompt fission gamma-rays from neutrons by applying the time-of-flight technique and high selectivity for isomeric gamma-decay. Possible applications in other domains, e.g. actinide sample characterisation, particle beam monitoring, PET and environmental monitoring.