High-Resolution Image Reconstruction with Unsupervised Learning and Noisy Data Applied to Ion-Beam Dynamics for Particle Accelerators
Authors: Francis Osswald, Mohammed Chahbaoui, Xinyi Liang
Organizations: IPHC · IPHC, CNRS Nuclei & Particules, Univ. of Strasbourg, 67000, Strasbourg, France · UNISTRA · University of Strasbourg, 67000, Strasbourg, France · SU · Sorbonne University, 75006 Paris, France
Image reconstruction in the presence of severe degradation remains a challenging inverse problem, particularly in beam diagnostics for high-energy physics accelerators. As modern facilities demand precise detection of beam halo structures to control losses, traditional analysis tools have reached their performance limits. This work reviews existing image-processing techniques for data cleaning, contour extraction, and emittance reconstruction, and introduces a novel approach based on convolutional filtering and neural networks with optimized early-stopping strategies in order to control overfitting. Despite the absence of training datasets, the proposed unsupervised framework achieves robust denoising and high-fidelity reconstruction of beam emittance images under low signal-to-noise conditions. The method extends measurable amplitudes beyond seven standard deviations, enabling unprecedented halo resolution.
This work was conducted under the auspices of the DOE SULI and Los Alamos National Laboratory LDRD programs and by LLNL under Contract DE-AC52-07NA27344.