SEM

This is an acronym for Secondary Emission Monitor. SEMs are diagnostic devices used to measure beam position in the Antiproton source transport and fixed target lines. They are close relatives of multiwires as found in the 750 keV, 400 MeV, and 8 GeV lines as well as Switchyard SWICs. The x y grids crosses 10 micron titanium strips with either a 1.5 or 3.0 mm grid spacing. The electronics includes modified up-based SWIC scanners as used in the fixed target experimental areas.