Aging materials to see how they change over time: this is the purpose of the Sirius electron accelerator from the École Polytechnique Irradiated Solids Laboratory (LSI). Electron irradiation can be used to study the flaws produced in radiated materials and the resulting property changes in real time and at low temperatures. This machine, which releases electrons between 150 keV and 2.5 MeV, can function for up to 300 days per year. It is available for use by many researchers from both France and farther afield, particularly in the nuclear and space sectors. The electron accelerator may be used alongside other irradiation equipment and is part of the National Network of Accelerators for the Study of Irradiated Materials (Réseau national d’accélérateurs pour les Étude des Matériaux sous Irradiation (Emir)).