Direct measurement of the d(alpha,gamma)6Li cross-section at astrophysical energies

Standard Big Bang nucleosynthesis predicts a very low abundance of the minor lithium isotope 6Li, which is instead believed to be produced by cosmic rays over time. However, recently 6Li has been detected in very old metal-poor stars, leading to the question whether its Big Bang production might be stronger than believed. The key reaction for 6Li production in the Big Bang is d(alpha,gamma)6Li. Using the deep underground LUNA 400 kV accelerator at the Gran Sasso Laboratory in Italy, a direct measurement of the cross section is underway. The contribution will report on this experiment, collected data, methods to analyze them, and preliminary results.