The design and performance of a halo-free intense extracted proton beam at Fermilab

A set of refocussing and collimation stages has been constructed in the Proton West beam line of the Proton Area at Fermi National Accelerator Laboratory which allows the operation of a halo-free intense proton beam. Measurements made at the first target point in the Proton West experimental hall demonstrate that this system is capable of targeting 1012 protons in a 4 mm diameter spot with a halo density of about 150 particles/mm2 at a distance of 5.6 cm from the focus. This system has been operated at 200, 300 and 400 GeV. (Auth.)