As explained by Eric Palm, Deputy Lab Director.
A "user" is a scientist, either from inside the laboratory or usually from outside the laboratory, who comes to use our facility to do their experiment. Our users come from all over the world. We have a broad selection of different universities that are able to use our facilities to do cutting-edge research. It would be prohibitively expensive to have very large magnets in everybody's home institution. So the National Science Foundation funds us to have these large magnets and the research facilities here. People can come from their home institutions and use the magnets and share the facilities. We have people in the DC Facility mostly doing physics, but a significant amount of materials research, and people doing some biological-based experiments. At the other end of the building, the NMR, ICR, EMR programs have a lot of chemistry, biology and other disciplines. We have over 1,000 users a year who come to the Magnet Lab to use our facilities.