Accurate measurement of the standard 235U(n,f) cross section from thermal to 170 keV neutron energy

S Amaducci,E Chiaveri,A Manna,G Tagliente,A Negret,A Stamatopoulos,T Wright,M Krtička,D Radeck,A Gawlik,T Glodariu,A Oprea,J Andrzejewski,E Mendoza,I F Gonçalves,S J Lonsdale,N Patronis,A Musumarra,G Vannini,F Mingrone,F Gunsing,V Variale,J Perkowski,D G Jenkins,S Valenta,J Billowes,F Käppeler,Y Kadi,J Marganiec,P Kavrigin,R Vlastou,M Bacak,C Rubbia,A Casanovas,P J Woods,D Macina,L Audouin,R Cardella,A Masi,V Furman,M Sabaté-Gilarte,H Leeb,J M Quesada,E Berthoumieux,F Calviño,M Mastromarco,M Caamaño,E Dupont,N V Sosnin,A Pavlik,M A Cortés-Girardo,S Heinitz,A Kalamara,F Bečvář,C Lederer,L A Damone,P Vaz,M Kokkoris,E Griesmayer,E Jericha,S Lo Meo,O Aberle,A Mazzone,S Warren,E Leal-Cidoncha ,A Brown,C Weiß ,A Saxena,A Mengoni,P Mastinu,D Bosnar,L Coséntino ,C Domingo‐Pardo ,P Schillebeeckx,J Praena,A Wallner,J Lerendegui-Marco ,K Göbel,I Durán,R Dressler,D Cano‐Ott ,L Tassan‐Got ,P Sedyshev,A Kimura,M Barbagallo,I Porras,R Reifarth,J A Ryan,S Gilardoni,D Schumann,N Colonna,J Balibrea,F Cerutti,Paulo Ricardo Araújo Ferreira ,G Cortés,N Kivel,Μ Diakaki ,C Massimi,Roeland J M Nolte ,E A Maugeri,M Calviani,J Heyse,T Rauscher,A Ferrari,P Finocchiaro,A R García ,E González‐Romero ,D Kurtulgil,V Vlachoudis,Andrew Smith ,Hideo Harada ,A Ventura,C Guerrero,Y H Chen,I Knapová ,A Tarifeño-Saldivia,B Fernández–Domínguez ,P Žugec,T Martínez,J L Taín ,Paolo Milazzo

doi:10.1051/epjconf/202023908002

Abstract

An accurate measurement of the 235U(n,f) cross section from thermal to 170 keV of neutron energy has recently been performed at n_TOF facility at CERN using 6Li(n,t)4He and 10B(n,α)7Li as references. This measurement has been carried out in order to investigate a possible overestimation of the 235U fission cross section evaluation provided by most recent libraries between 10 and 30 keV. A custom experimental apparatus based on in-beam silicon detectors has been used, and a Monte Carlo simulation in GEANT4 has been employed to characterize the setup and calculate detectors efficiency. The results evidenced the presence of an overestimation in the interval between 9 and 18 keV and the new data may be used to decrease the uncertainty of 235U(n,f) cross section in the keV region.

Highlights

Most of the neutron cross sections are measured using a standard reaction as reference, i.e. a small group of reactions know with high accuracy in a well defined energy interval [1] [2]
Recent experimental data [3] highlighted a possible overestimation of the 235U fission cross section in the major libraries in the neutron energy range between 10 and 30 keV
Even if in this interval the 235U(n,f) is not a standard, it is still often used as reference, in particular for capture and fission cross section measurements of actinides. This energy interval is interesting for many technological applications, in particular for the design of new generation fission reactors and for nuclear waste burning, which require accurate neutron cross section data

Summary

Introduction

Most of the neutron cross sections are measured using a standard reaction as reference, i.e. a small group of reactions know with high accuracy in a well defined energy interval [1] [2]. Recent experimental data [3] highlighted a possible overestimation of the 235U fission cross section in the major libraries in the neutron energy range between 10 and 30 keV. Even if in this interval the 235U(n,f) is not a standard, it is still often used as reference, in particular for capture and fission cross section measurements of actinides. This energy interval is interesting for many technological applications, in particular for the design of new generation fission reactors and for nuclear waste burning, which require accurate neutron cross section data

Methods

Results

Conclusion