Mass measurements of neutron-rich Rb and Sr isotopes

• Main Authors: Klawitter, R, Bader, A, Brodeur, M, Chowdhury, U, Chausdhuri, A, Fallis, J, Gallant, A. T, Grossheim, A, Kwiatkowski, A. A, Lascar, D, Leach, K. G, Lennarz, A, Macdonald, T. D, Pearkes, J, Seeraji, S, Simon, M. C, Simon, V. V, Schultz, B. E, Dilling, J
• Format: Journal Article
• Language: English
• Published: 22-12-2015
• Subjects: Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.1512.07105

Phys. Rev. C 93, 045807 (2016) We report on the mass measurements of several neutron-rich $\mathrm{Rb}$ and
$\mathrm{Sr}$ isotopes in the $A \approx 100$ region with the TITAN
Penning-trap mass spectrometer. Using highly charged ions in the charge state
$q=10+$, the masses of $^{98,99}\mathrm{Rb}$ and $^{98-100}\mathrm{Sr}$ have
been determined with a precision of $6 - 12\ \mathrm{keV}$, making their
uncertainty negligible for r-process nucleosynthesis network calculations. The
mass of $^{101}\mathrm{Sr}$ has been determined directly for the first time
with a precision eight times higher than the previous indirect measurement and
a deviation of $3\sigma$ when compared to the Atomic Mass Evaluation. We also
confirm the mass of $^{100}\mathrm{Rb}$ from a previous measurement.
Furthermore, our data indicates the existance of a low-lying isomer with $80\
\mathrm{keV}$ excitation energy in $^{98}\mathrm{Rb}$. We show that our updated
mass values lead to minor changes in the r-process by calculating fractional
abundances in the $A\approx 100$ region of the nuclear chart.