The measurement of the 206Pbn, gamma cross section and stellar implications

C. Domingo-Pardo , U. Abbondanno , G. Aerts (1) , H. Álvarez , F. Alvarez-Velarde , S. Andriamonje (1) , J. Andrzejewski , P. Assimakopoulos , L. Audouin , G. Badurek , P. Baumann (2) , F. Becvar , E. Berthoumieux (1) , S. Bisterzo , F. Calviño , M. Calviani , D. Cano-Ott , R. Capote , C. Carrapico , P. Cennini , V. Chepel , N. Colonna , G. Cortes , A. Couture , J. Cox , M. Dahlfors , S. David (3) , I. Dillmann , W. Dridi (1) , I. Duran , C. Eleftheriadis , M. Embid-Segura , L. Ferrant (3) , Anthony Ferrari , R. Ferreira-Marques , K. Fujii , W. Furman , R. Gallino , I. Goncalves , E. Gonzalez-Romero , F. Gramegna , C. Guerrero , F. Gunsing (1) , B. Haas (4) , R. Haight , M. Heil , A. Herrera-Martinez , M. Igashira , E. Jericha , Y. Kadi , F. Käppeler , D. Karadimos , D. Karamanis , M. Kerveno (2) , P. Koehler , E. Kossionides , M. Krticka , C. Lamboudis , H. Leeb , A. Lindote , I. Lopes , M. Lozano , S. Lukic (2) , J. Marganiec , S. Marrone , C. Massimi , P. Mastinu , A. Mengoni , P. M Milazzo , M. Mosconi , F. Neves , H. Oberhummer , S. O'Brien , J. Pancin (1) , C. Papachristodoulou , C. Papadopoulos , C. Paradela , N. Patronis , A. Pavlik , P. Pavlopoulos , L. Perrot (1) , M. T Pigni , R. Plag , A. Plompen , A. Plukis (1) , A. Poch , C. Pretel , J. Quesada , T. Rauscher , R. Reifarth , C. Rubbia , G. Rudolf (2) , P. Rullhusen , J. Salgado , C. Santos , L. Sarchiapone , I. Savvidis , C. Stephan (3) , G. Tagliente , J. L Tain , L. Tassan-Got (3) , L. Tavora , R. Terlizzi , G. Vannini , P. Vaz , A. Ventura , D. Villamarin , M. C Vincente , V. Vlachoudis , R. Vlastou , F. Voss , S. Walter , M. Wiescher , K. Wisshak

1 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
2 DRS-IPHC - Département Recherches Subatomiques
3 IPNO - Institut de Physique Nucléaire d'Orsay
4 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

The neutron capture cross section of 206Pb has been measured at the CERN n\TOF spectrometer using a setup of two C6D6 detectors. In the energy interval from 1 eV to 600 keV the cross section is dominated by resonances, which were analyzed via the R-matrix analysis code SAMMY. In the relevant energy ranges for stellar nucleosynthesis, i.e., at thermal energies of kT = 8 keV and kT = 23 keV, the present Maxwellian average cross section differs by 20% and 9% from the recommended values of Bao et al respectively. From the new cross section the s-abundance of 206Pb could be reliably determined as 70(4)%. This result is of importance in order to test and constrain r-process abundance calculations in the actinide region, because the r-process portion of 206Pb is dominated by α-back decays of short-lived transbismuth isotopes.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

C. Domingo-Pardo, U. Abbondanno, G. Aerts, H. Álvarez, F. Alvarez-Velarde, et al.. The measurement of the 206Pbn, gamma cross section and stellar implications. Journal of Physics G: Nuclear and Particle Physics, 2008, 35, pp.014020. ⟨10.1088/0954-3899/35/1/014020⟩. ⟨in2p3-00197132⟩