Cross section measurements of $^{155,157}$Gd(n, $\gamma$) induced by thermal and epithermal neutrons

M. Mastromarco , A. Manna , O. Aberle , J. Andrzejewski , L. Audouin (1) , M. Bacak (2) , J. Balibrea , M. Barbagallo , F. Bečvář , E. Berthoumieux (2) , J. Billowes , D. Bosnar , A. Brown , M. Caamaño , F. Calviño , M. Calviani , D. Cano-Ott , R. Cardella , A. Casanovas , D.M. Castelluccio , F. Cerutti , Y.H. Chen (1) , E. Chiaveri , G. Clai , N. Colonna , G. Cortés , M.A. Cortés-Giraldo , L. Cosentino , L.A. Damone , M. Diakaki (2) , C. Domingo-Pardo , R. Dressler , E. Dupont (2) , M. Dietz , I. Durán , B. Fernández-Domínguez , A. Ferrari , P. Ferreira , P. Finocchiaro , V. Furman , K. Göbel , A.R. García , A. Gawlik , S. Gilardoni , T. Glodariu , I.F. Gonçalves , E. González-Romero , E. Griesmayer , C. Guerrero , A. Guglielmelli , F. Gunsing (2) , H. Harada , S. Heinitz , J. Heyse , D.G. Jenkins , E. Jericha , F. Kaeppeler , Y. Kadi , A. Kalamara , P. Kavrigin , A. Kimura , N. Kivel , M. Kokkoris , M. Krtička , D. Kurtulgil , E. Leal-Cidoncha , C. Lederer-Woods , H. Leeb , J. Lerendegui-Marco , S.J. Lonsdale , D. Macina , J. Marganiec , T. Martínez , A. Masi , C> Massimi , P. Mastinu , E.A. Maugeri , A. Mazzone , E. Mendoza , A. Mengoni , P.M. Milazzo , F. Mingrone , A. Musumarra , A. Negret , R. Nolte , A. Oprea , N. Patronis , A. Pavlik , J. Perkowski , I. Porras , J. Praena , J.M. Quesada , D. Radeck , T. Rauscher , R. Reifarth , F. Rocchi , C. Rubbia , J.A. Ryan , M. Sabaté-Gilarte , A. Saxena , P. Schillebeeckx , D. Schumann , P. Sedyshev , A.G. Smith , N.V. Sosnin , A. Stamatopoulos , G. Tagliente , J.L. Tain , A. Tarifeño-Saldivia , L. Tassan-Got (1) , S. Valenta , G. Vannini , V. Variale , P. Vaz , A. Ventura , V. Vlachoudis , R. Vlastou , A. Wallner , S. Warren , C. Weiss , P.J. Woods , T. Wright , P. Žugec

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers

Neutron capture cross section measurements on$^{155}$Gd and$^{157}$Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n_TOF experimental area EAR1, at 185 m from the neutron source, with an array of 4 C$_{6}$D$_{6}$ liquid scintillation detectors. At a neutron kinetic energy of 0.0253 eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for$^{155}$Gd and$^{157}$Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181 eV and 307 eV, respectively for$^{155}$Gd and$^{157}$Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1 keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of $2.01(28) \times 10^{-4}$ and $2.17(41) \times 10^{-4}$ , average total radiative width of 106.8(14) meV and 101.1(20) meV and s-wave resonance spacing 1.6(2) eV and 4.8(5) eV for n +$^{155}$Gd and n +$^{157}$Gd systems, respectively.

Mots clés: resonance: energy; energy: kinetic; scintillation counter: liquid; n: capture; shape analysis; time-of-flight; CERN Lab; thermal; experimental results

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

M. Mastromarco, A. Manna, O. Aberle, J. Andrzejewski, L. Audouin, et al.. Cross section measurements of $^{155,157}$Gd(n, $\gamma$) induced by thermal and epithermal neutrons. Eur.Phys.J.A, 2019, 55 (1), pp.9. ⟨10.1140/epja/i2019-12692-7⟩. ⟨hal-01801879⟩