Mass measurements of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ga</mml:mi><mml:mprescripts /><mml:none /><mml:mrow><mml:mn>60</mml:mn><mml:mtext>–</mml:mtext><mml:mn>63</mml:mn></mml:mrow></mml:mmultiscripts></mml:math> reduce x-ray burst model uncertainties and extend the evaluated <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>T</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math> isobaric multiplet mass …

We report precision mass measurements of neutron-deficient gallium isotopes approaching the proton drip line. The Ga60–63 performed with TITAN multiple-reflection time-of-flight spectrometer provide a more than threefold improvement over current literature uncertainty Ga61 and mark first direct measurement Ga60. improved has important implications for astrophysical rp process, as it constrains essential reaction Q values near Zn60 waiting point. Based on calculations one-zone model, we demonstrate impact data prediction uncertainties x-ray burst models. first-time Ga60 ground-state establishes proton-bound nature this nuclide, thus constraining location line along isotopic chain. Including measured further enables us to extend evaluated T=1 isobaric multiplet equation up A=60.Received 14 August 2021Revised 22 October 2021Accepted 16 November 2021DOI:https://doi.org/10.1103/PhysRevC.104.065803©2021 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBinding energy & massesCoulomb energies analogue statesModels based symmetriesNuclear astrophysicsNuclear physics explosive environmentsNuclear reactionsNucleosynthesis in environmentsShell modelProperties59 ? A 89MassTechniquesMass spectrometryTime-of-flight spectrometryNuclear Physics