Charged particles are swept into a the focal plane charged particle detectors by the Sweeper magnet.
The sweeper magnet was designed and built at the National high Magnetic field Laboratory at Florida State University. Below are three views of the magnet. The sweeper magnet is a Nb-Ti superconducting magnet cooled with liquid He. It has a maximum field of approximately 3.5 Tesla.
The image below shows the sweeper magnet in position in the MoNA Facility vault.