PSI is the largest research center for natural and engineering sciences in Switzerland, conducting cutting-edge research in three main fields: matter and materials, energy and environment, and human health. PSI runs Switzerland's large scale research facilities (LSFs) for users from the national and international scientific community and is one of the very few locations in the world providing a neutron spallation source (SINQ), a synchrotron (the Swiss light source or SLS), a muon source (SμS), and an X-ray free electron laser (SwissFEL).