Penning-trap mass spectrometry of highly charged, neutron-rich Rb and Sr isotopes in the vicinity of $A\approx 100$

Abstract

The neutron-rich mass region around $A\approx 100$ presents challenges for modeling the astrophysical $r$-process because of rapid shape transitions. We report on mass measurements using the TITAN Penning trap at TRIUMF-ISAC to attain more reliable theoretical predictions of $r$-process nucleosynthesis paths in this region. A new approach using highly charged ($q=15+$) ions has been applied which considerably saves measurement time and preserves accuracy. New mass measurements of neutron-rich ${}^{94,97,98}$Rb and ${}^{94,97-99}$Sr have uncertainties of less than 4 keV and show deviations of up to 11$\sigma$ to previous measurements. An analysis using a parameterized $r$-process model is performed and shows that mass uncertainties for the A=90 abundance region are eliminated.

References in corpus (6)

• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• First Penning-trap mass measurement in the millisecond half-life range: the exotic halo nucleus 11Li
• Half-lives and branchings for β-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process
• Collectivity-induced quenching of signatures for shell closures
• Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path
• Shape evolution in Yttrium and Niobium neutron-rich isotopes

Cited by in corpus (2)

• Horizons: Nuclear Astrophysics in the 2020s and Beyond
• Prominent bump in the two-neutron separation energies of neutron-rich lanthanum isotopes revealed by high-precision mass spectrometry