(α,n) data for applications and detector simulation codes

Knowledge on ($\alpha$,Xn) reactions is required in several fields: - Nuclear structure. Most of our actual experimental knowledge on (α,Xn) reactions comes from nuclear structure experiments between the 50's and the 70's. Nuclear technologies, non-proliferation and homeland security. $\alpha$-emitters present in fresh/irradiated nuclear fuels can create a neutron source through ($\alpha$-,Xn) reactions with (light) surrounding nuclei: fluorine, oxide and carbide fuels, vitrified nuclear waste… - Determination of the $^{235}$U enrichment. - Analysis of irradiated fuels, MOX fuels and fuels enriched in MA. - Neutron background in underground experiments (nuclear astrophysics, Dark Matter) due to radiogenic $\alpha$-decay chains. We will present some examples of applications and the SaG4n tool, a GEANT4-based parser that allows to perform realistic simulations of ($\alpha$,n) yields.