First direct mass measurement of the neutron-deficient nucleus Al24

The first direct mass measurement of the neutron-deficient nucleus Al24 was performed via Penning-Trap Mass Spectrometry (PTMS) using TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). This measurement was facilitated by the use of TRIUMF's new Ion-Guide Laser Ion Source (IG-LIS), which reduced A=24 isobaric contamination in the delivered beam by nearly six orders of magnitude. The measured mass excess was found to be Δ=−48.86(23) keV, which is five times more precise than the value quoted in the most recent atomic mass evaluation. When combined with the relevant Al24 excitation energy, and a recent measurement of the Mg23 mass, the astrophysical Mg23(p,γ)24Al reaction resonance energy is extracted as Er=480.8(14) keV. The presented value shows a 2σ disagreement with the direct measurement of this quantity by the DRAGON recoil spectrometer.