AMS cross-section measurement for the $$^{28}$$Si(d,$$\alpha $$)$$^{26}$$Al reaction near the Coulomb barrier

Abstract

Understanding the production of $$^{26}$$ Al is important in nuclear physics, astrophysics (stellar nucleosynthesis), earth sciences and other fields. In previous years, we attempted to measure the $$^{28}$$ Si(d, $$\alpha $$ ) $$^{26}$$ Al reaction cross section at low energies. AMS (Accelerator Mass Spectrometry) at the LEMA (Laboratorio Nacional de Espectrometrometria de Masas con Aceleradores) facility at IFUNAM (Instituto de Fisica, Universidad Nacional Autonoma de Mexico) was used to measure the concentration of the produced $$^{26}$$ Al in a mixture of Al/Si targets after irradiation with a deuteron beam. Those measurements showed that many improvements had to be made to our protocols in order to reach our goal. In this paper, the continuation of those studies is reported. We take advantage of the recently acquired expertise in the radio-chemistry process to separate aluminum from silicon. Deuteron beams with energies between 3.4 and 4.8 MeV were used to irradiate 5 $$\times $$ 5 $$\times $$ 0.3 mm $$^{3}$$ silicon slabs. Considering that the Coulomb barrier for touching spheres is around 4.7 MeV, our experiment explores an energy interval near the barrier, on the lower energy side. Here reaction cross sections are much larger than those expected at lower energies, toward the Gamow window, an energy range appropriate to develop and test the project’s strategy before tackling the lower energies (most relevant for astrophysics) where the cross sections drop exponentially.