Precision mass measurements of $^{74-76}$Sr using TITAN's Multiple-Reflection Time-of-Flight Mass Spectrometer

TL;DR

This paper reports high-precision mass measurements of isotopes $^{74-76}$Sr using TITAN's advanced spectrometer, providing new data for nuclear structure analysis and astrophysical modeling of rapid proton capture processes.

Contribution

It presents the first mass measurement of $^{74}$Sr, improves precision for $^{75}$Sr and $^{76}$Sr, and evaluates isobaric multiplet mass equations at A=74 and 75.

Findings

Confirmed recent $^{75}$Sr mass measurement, removing previous anomalies.

Completed the A=74, T=1 isospin triplet data for the first time.

Provided new theoretical calculations and implications for astrophysical processes.

Abstract

We report precision mass measurements of $^{74-76}$Sr performed with the TITAN Multiple-Reflection Time-of-Flight Mass Spectrometer. This marks a first time mass measurement of $^{74}$Sr and gives increased mass precision to both $^{75}$Sr and $^{76}$Sr which were previously measured using storage ring and Penning trap methods, respectively. This completes the A = 74, T = 1 isospin triplet and gives increased precision to the A = 75, T = 1/2 isospin doublet which are both the heaviest experimentally evaluated triplets and doublets to date. The new data allow us to evaluate coefficients of the isobaric multiplet mass equation for the first time at A = 74, and with increased precision at A = 75. With increased precision of 75Sr, we confirm the recent measurement reported by CSRe which was used to remove a staggering anomaly in the doublets. New ab initio valence-space in-medium similarity renormalization group calculations of the T = 1 triplet are presented at A = 74. We also investigate the impact of the new mass data on the reaction flow of the rapid proton capture process in type I x-ray bursts using a single-zone model.