Study of the contribution of the Be-7(d, p) reaction to the Li-7 problem in the Big-Bang Nucleosynthesis

Our research goal is to measure the cross section of the Be-7(d, p) reaction to find a solution for the cosmological the 7 Li problem, which is an overestimation of the primordial Li-7 abundance in the standard Big-Bang nucleosynthesis (BBN) model. We developed a method to produce an unstable Be-7 target to measure the reaction in normal kinematics in a high-resolution measurement. We performed an experiment to produce the Be-7 target and also to measure the cross section of the Be-7(d, p) Be-8 reaction with the produced Be-7 target at the tandem facility, Kobe University. A 2.36 MeV proton beam irradiated a Li target to transmute Li-7 particles to Be-7 particles via the Li-7(p, n) Be-7 reaction. We produced 2.6x 10(13) Be-7 particles in the target after two days' proton irradiation. After the target production, the beam ion was changed to deuterons with energies of 0.6, 1.0, and 1.6 MeV to measure the Be-7(d, p) reaction. The outgoing protons were measured by two Delta E-E silicon telescopes placed at 30 degrees and 45 degrees. We report the preliminary results of this experiment, including the Be-7(d, p) cross section.