Precision $\beta$-delayed charged-particle emission spectroscopy at FRIB: Proof of principle with the $\beta$-decay of ${}^{25}\mathrm{Si}$

Abstract

We report on the $\beta$-delayed proton and $\gamma$-ray emission from ${}^{25}\mathrm{Si}$, measured at the Facility for Rare Isotope Beams (FRIB). Low-energy ${}^{25}\mathrm{Si}$ ions extracted from the Advanced Cryogenic Gas Stopper were implanted into a thin carbon foil surrounded by a compact, highly segmented array of silicon detector telescopes and two high-purity germanium detectors. This setup provides high-resolution charged-particle spectroscopy, establishing a proof of principle for precision stopped-beam decay studies at FRIB. We reconstruct the ${}^{25}\mathrm{Si}$ decay scheme, resolving new high-energy proton transitions and determining the feeding to excited states in ${}^{24}\mathrm{Mg}$. The observation of spectral interference patterns enables firm spin and parity assignments for highly excited states in ${}^{25}\mathrm{Al}$. The ${}^{25}\mathrm{Si}$ $\beta$-strength distribution is extracted and compared with large-scale shell-model calculations.

Comments: 22 pages, 16 figures