Aperture limitation localization using beam position and beam loss monitor measurements

The efficiency of beam injection in circular accelerators can be impacted by unknown aperture limitations in the vacuum chamber. These limitations can be detected by introducing localized distortions to the closed orbit of the circulating beam observed at beam position monitors (BPMs). The localized nature of introduced closed orbit distortions enables targeted identification of loss regions. In this paper, we present a method for localizing beam losses designed primarily for circular electron accelerators using a set of sequentially placed scintillator-based beam loss monitors (BLMs). By moving these monitors along the accelerator lattice, the proposed technique achieves sub-meter spatial resolution in beam loss localization. Relative calibration of the BLMs was performed using a strontium-90 radioactive source. We report experimental results from the implementation of this method at the VEPP-4M collider.