Testing and calibration of a Faraday cup and other intensity monitors for the external proton beam at LAMPF

Three different methods of measuring beam intensities have been tested in the external proton beam at the Los Alamos Meson Physics Facility (LAMPF) over a wide range of beam currents. A 700 kg Faraday cup was constructed and has been demonstrated to be capable of absolute measurements with an error lower than 1%. A high gain Ar-CO2 ion chamber was built for low beam intensity monitoring (down to a few pA) and provided an independent check of the Faraday cup calibration to better than 3%. A secondary emission monitor was also tested and calibrated relative to the Faraday cup. This secondary emission monitor provides reliable data for beams greater than about 50 pA. (Auth.)