Transverse profile monitor using ion probe beams

A profile monitor is described that makes use of a low-intensity and low-energy ion beam to measure the transverse profile of a dense proton beam of small dimensions. Three techniques are considered based on the use of ion beams having a pencil, curtain, or cylindrical shape. The detector is almost non-interceptive for the proton beam and does not introduce disturbances in the machine environment. The theoretical aspects of the techniques used, together with experimental results obtained at the CERN SPS and Linac, are presented.