It depends. Big infrastructures usually provide a whole range of services to different target groups. They have set tariffs for researchers who want to use the facilities for their research. Often, researchers from all over the world are welcome. For instance, at the Swiss Light Source (SLS) infrastructure, researchers can use the facility for free for their research if the publication of the results is done with the logo of the infrastructure. Researchers stay usually around one week on the site for their research and the infrastructure welcomes around 250 researchers per week (there is 80 permanent staff to run the facility). There is collaboration of SLS with infrastructures in other fields of research, e.g. the Basel Kantonsspital for medical application of research in physics. The collaboration includes exchange of researchers and common seminars. Major research infrastructures in Europe are also equipped and organized for public visits (e.g. CERN Geneva programme of visits free of charge for schools and general public).