The²⁸Si(d,α) reaction

Abstract

Abstract. Recent techniques and experimental methods open up new ways to explore nuclear reactions relevant to nucleosynthesis at stellar combustion temperatures. In this work we focus on the case of 26 Al, isotope associated with the identification of active nucleosynthesis spots in the cosmos. Its presence in the solar system was unexpected until it was found in the Allende meteorite. It is now understood that cosmic rays induce nuclear reactions to produce 26 Al. On Earth, this process is well known and is the basis of many environmental studies. So 26 Al is not just the product of some high-metallicity star collapse. Natural Silicon targets were irradiated with deuteron beams of energies between 0.9 and 2.6 MeV. The produced 26 Al were counted later-on in an AMS facility. In this paper, we describe in detail the experimental protocol developed to quantify the number of deuterons hitting the target, as a first step to determine the total cross section.

Monoisotopic targets production from atomic and molecular positive ion implantation in a tandem accelerator at low energies

“…Here we cannot use a carbon matrix, so aluminum was chosen. This choice is particularly well suited for nuclear reaction studies on 13 C at low energies since the nuclei in the matrix present a Coulomb Barrier twice as high as that of 13 C, strongly suppressing possible contamination of the data with spurious reactions. In turn, the RBS analysis becomes harder to do for the same reason.…”

“…Figure 2 shows the RBS analysis spectrum obtained with 1.035 MeV protons (data and SIMNRA simulation) of the 13 C implanted target on aluminum. The areal density achieved in this case is (9.4±13)×10 16 atoms/cm 2 which is also useful for many nuclear reaction studies.…”

“…Thousands of samples have been analyzed, some of the more relevant results in applied and interdisciplinary research produced in this facility can be found in [6,7,8,9,10,11,12]. This facility has also been useful for fundamental nuclear physics research [13,14,15,16,17].…”

Reaction production + AMS: An alternative method to study low energy reactions.26Al as a test case

“…A series of target/cathodes were mounted (one by one) inside a vacuum chamber to be irradiated for periods of 2 hours with a deuterium beam of an average intensity of 200 nA. A detailed description of this procedure is well described in [6,7]. In order to monitor the reaction behaviour, two PIP-silicon detectors were placed symmetrically at 150º in both backward sides of the target/cathode.…”