Optical Image Postprocessing Methods for Beam Diagnostics by the Example of a Proton Beam Induced Fluorescence Monitor

To carry out nondestructive measurements of the profile and position of a proton beam at the low-energy transport channel of the linear accelerator at the Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), a fluorescence monitor based on the fluorescence of residual gas in a vacuum chamber of the channel is used. The data postprocessing methods that allow the beam boundaries to be detected at noisy optical images with a nonuniform background are compared. A comparison of effectiveness of the methods is performed using a test set of generated images and the experimental images recorded during the accelerator operation sessions. The conditions under which each method successfully copes with the beam boundary detection are described. The feasibility of using bandpass filtering to detect beam boundaries on the experimental images recorded by the fluorescence monitor is demonstrated.