Direct cross section measurement of ${}^{13}C(\alpha,n)^{16}O$ at low energies.

The ${}^{13}C(\alpha,n)^{16}O$ reaction has a very important astrophysical context for the synthesis of the main s-process component of heavy elements. While remarkable results have been achieved by the low-energy measurement of this reaction, ultimately the environmental background has been a limiting factor. The LUNA Collaboration measured the ${}^{13}C(\alpha,n)^{16}O$ in the low-background environment of the LNGS. This unique location, with a high-efficiency low-background detector and state-of-the-art electronics, has already enabled us to push the low-energy cross section limit beyond what has been reached before. Here we present the current status of the experiment and the preliminary results.