Atomic beams lie at the very foundation of most measurements in atomic physics. Rydberg atoms, in turn, are central to a wide range of challenges: quantum control, sensing, charge exchange, and the production of ion and/or electron beams. The proposed project aims to optimize an atomic beam, relying for instance on microchannels, which should significantly improve the beam collimation. Other techniques, such as magnetic compression or transverse (2D) laser cooling and guiding, may also be investigated. The goal is to obtain an intense, dense Cs or Rb atomic beam in the Rydberg excitation region. The experiment will then be transferred to different setups, such as an innovative electron microscope, the HREELM (High-Resolution Electron Energy Loss Microscope). This microscope detects very low-energy electrons with excellent time resolution. The objective is to exploit the space-time correlation between a Rydberg atom and its electron, obtained by ionizing the atom, in order to improve the electron source.