Measurement of Mg-25(p, gamma)Al-26(g) resonance strengths via accelerator mass spectrometry

The strengths of resonances located at center-of-mass energies of E-c.m.=189, 304, 374, and 418 keV for the Mg-25(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 Al-26(g) nuclei were counted by means of highly sensitive accelerator mass spectrometry (AMS). Thus, the production of Al-26 in its ground state is determined independently from the gamma-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.