6533b7d2fe1ef96bd125ee60
RESEARCH PRODUCT
Precision Mass Measurements on Neutron-Rich Rare-Earth Isotopes at JYFLTRAP : Reduced Neutron Pairing and Implications for r-Process Calculations
Markus VilénJ. M. KellyAnu KankainenM. BrodeurA. AprahamianLaetitia CaneteTommi EronenAri JokinenT. KutaIain MooreM. R. MumpowerDmitrii NesterenkoHeikki PenttiläIlkka PohjalainenW. S. PorterSami Rinta-antilaR. SurmanAnnika VossJuha ÄYstösubject
astrofysiikkanuclear astrophysicsharvinaiset maametallitydinfysiikkabinding energy and massesdescription
The rare-earth peak in the r-process abundance pattern depends sensitively on both the astrophysical conditions and subtle changes in nuclear structure in the region. This work takes an important step towards elucidating the nuclear structure and reducing the uncertainties in r-process calculations via precise atomic mass measurements at the JYFLTRAP double Penning trap. Nd158, Pm160, Sm162, and Gd164-166 have been measured for the first time, and the precisions for Nd156, Pm158, Eu162,163, Gd163, and Tb164 have been improved considerably. Nuclear structure has been probed via two-neutron separation energies S2n and neutron pairing energy metrics Dn. The data do not support the existence of a subshell closure at N=100. Neutron pairing has been found to be weaker than predicted by theoretical mass models. The impact on the calculated r-process abundances has been studied. Substantial changes resulting in a smoother abundance distribution and a better agreement with the solar r-process abundances are observed. peerReviewed
year | journal | country | edition | language |
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2018-01-01 |