The strengths of resonances located at center-of-mass energies of $E_{c.m.}=189$, 304, 374, and 418 keV for the ${}^{25}\mathrm{Mg}$($p$,$\gamma )$ reaction have been measured for the first time with an off-line method: Mg targets were firstly activated with protons at the resonance energies and the produced ${}^{26}\mathrm{Al}$${}^g$ nuclei were counted by means of highly sensitive accelerator mass spectrometry (AMS). Thus, the production of ${}^{26}\mathrm{Al}$ in its ground state is determined independently from the γ-decay branching ratio. While the 304, 374, and 418 keV resonances show fair agreement with previous measurements, the 189 keV resonance yield a significantly less strength. In addition, an experimental upper limit for the $E_{c.m.}=92$ keV resonance was determined.

• Received 3 April 2006

DOI:https://doi.org/10.1103/PhysRevC.74.025802