Show simple item record

dc.contributor.authorRauscher, T.
dc.date.accessioned2013-10-17T12:00:44Z
dc.date.available2013-10-17T12:00:44Z
dc.date.issued2013-08-09
dc.identifier.citationRauscher , T 2013 , ' Solution of the alpha-potential mystery in the gamma-process and its impact on the Nd/Sm ratio in meteorites ' , Physical Review Letters , vol. 111 , no. 6 , 061104 . https://doi.org/10.1103/PhysRevLett.111.061104
dc.identifier.issn0031-9007
dc.identifier.otherPURE: 2087875
dc.identifier.otherPURE UUID: 1ed506e8-a9a1-48ee-885d-d7a6b60b6756
dc.identifier.otherScopus: 84881537411
dc.identifier.urihttp://hdl.handle.net/2299/11808
dc.description.abstractThe 146Sm/144Sm ratio in the early solar system has been constrained by Nd/Sm isotope ratios in meteoritic material. Predictions of 146Sm and 144Sm production in the gamma-process in massive stars are at odds with these constraints and this is partly due to deficiences in the prediction of the reaction rates involved. The production ratio depends almost exclusively on the (gamma,n)/(gamma,alpha) branching at 148Gd. A measurement of 144Sm(alpha,gamma)148Gd at low energy had discovered considerable discrepancies between cross section predictions and the data. Although this reaction cross section mainly depends on the optical alpha+nucleus potential, no global optical potential has yet been found which can consistently describe the results of this and similar alpha-induced reactions at the low energies encountered in astrophysical environments. The untypically large deviation in 144Sm(alpha,gamma) and the unusual energy dependence can be explained, however, by low-energy Coulomb excitation which is competing with compound nucleus formation at very low energies. Considering this additional reaction channel, the cross sections can be described with the usual optical potential variations, compatible with findings for (n,alpha) reactions in this mass range. Low-energy (alpha,gamma) and (alpha,n) data on other nuclei can also be consistently explained in this way. Since Coulomb excitation does not affect alpha-emission, the 148Gd(gamma,alpha) rate is much higher than previously assumed. This leads to small 146Sm/144Sm stellar production ratios, in even more pronounced conflict with the meteorite data.en
dc.format.extent5
dc.language.isoeng
dc.relation.ispartofPhysical Review Letters
dc.rights/dk/atira/pure/core/openaccesspermission/open
dc.titleSolution of the alpha-potential mystery in the gamma-process and its impact on the Nd/Sm ratio in meteoritesen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionScience & Technology Research Institute
dc.contributor.institutionCentre for Astrophysics Research
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Astronomy and Mathematics
dc.description.versiontypeFinal Accepted Version
rioxxterms.versionAM
rioxxterms.versionofrecordhttps://doi.org/10.1103/PhysRevLett.111.061104
rioxxterms.typeOther
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeopenAccess


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record