Measurement and analysis of 155,157Gd(n,γ) from thermal energy to 1 keV

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

doi:10.1051/epjconf/202023901041

Abstract

We have measured the capture cross section of the 155Gd and 157Gd isotopes between 0.025 eV and 1 keV. The capture events were recorded by an array of 4 C6D6 detectors, and the capture yield was deduced exploiting the total energy detection system in combination with the Pulse Height Weighting Techniques. Because of the large cross section around thermal neutron energy, 4 metallic samples of different thickness were used to prevent problems related to self-shielding. The samples were isotopically enriched, with a cross contamination of the other isotope of less than 1.14%. The capture yield was analyzed with an R-Matrix code to describe the cross section in terms of resonance parameters. Near thermal energies, the results are significantly different from evaluations and from previous time-of-flight experiments. The data from the present measurement at n_TOF are publicly available in the experimental nuclear reaction database EXFOR.

Highlights

In this conference proceedings we prove the quality of the R-matrix analysis of the experimental data and provide required details to use the n_TOF data available on EXFOR for future evaluations
It can be argued that at thermal energy the uncertainty component (v) due to neutron flux shape already incorporates the uncertainty component (vi) related to the beam interception factor and the total uncertainty is slightly lower than reported in ref. [9] being reduced to 3% and 3.4%, respectively for the thermal cross section of 155Gd(n,γ) and 157Gd(n,γ)
From a simultaneous resonance shape analysis of the capture yields, using the R-Matrix code SAMMY, the cross sections were parametrized in terms of resonance parameters in the energy region from thermal to 1 keV neutron

Summary

Introduction

The values of the 155Gd and 157Gd thermal cross sections retrieved from the experimental nuclear reaction database EXFOR [3] reported in refs. The tabulated cross sections show that large deviations, as high as 11%, with respect to the last evaluation, namely ENDF/B-VIII.0, are present in literature. The request for high accuracy data for the gadolinium isotopes with the largest capture cross section [15] motivated a new measurement of these two isotopes at the neutron time-of-flight facility n_TOF [16] at CERN. In this conference proceedings we prove the quality of the R-matrix analysis of the experimental data and provide required details to use the n_TOF data available on EXFOR for future evaluations

Results

Discussion

Conclusion