Fast reconstruction of beams in intense proton accelerators

Conventional methods of monitoring beam locations in a pipe involve measuring signals from strip lines or taking the image of a fluorescent screen inside the beam vacuum pipe. However, these methods, which are called invasive, cannot be applied to the intense proton accelerator dealing with 1.5 GeV. This paper introduces a fast noninvasive method of reconstructing the beam from measurements of the magnetic field, produced by the beam, outside the vacuum pipe. The proposed reconstruction method is based on a Gauss-Newton scheme in addition with a variance uniformization constraint (which will be derived in this paper) to overcome the ill-posed nature of the problem. With this method, the location of the beam within the beam pipe can be reconstructed with satisfying accuracy after just one Gauss-Newton step.