Scientific Highlights PSI logo Highlights Featured NUM NUM is the organisational home base for the research at PSI, which is based on the use of the PSI High Intensity Proton Accelerator HIPA and which spans the entire range from particle physics via solid, liquid or soft condensed matter science, chemistry, materials science and engineering to cultural heritage. GFA The Division of Large Research Facilities (GFA) is responsible for the construction, operation and development of the particle accelerators at PSI. Swiss Light Source The Swiss Light Source (SLS) at the Paul Scherrer Institut is a third-generation synchrotron light source. In the design of SLS a high priority was given to the items quality (high brightness), flexibility (wide wavelength spectrum) and stability (very stable temperature conditions) for the primary electron beam and the secondary photon beams. SwissFEL SwissFEL is Switzerland's X-ray free-electron laser (FEL) facility at the Paul Scherrer Institute in Villigen and part of the Photon Science Division. Experiments at the Swiss Free-Electron Laser will lead to an entirely new level of understanding of matter in biology, chemistry, engineering and materials science.