Analysis and correction of intrinsic measurement errors for the dipole-magnet-based energy analysis system on HuTeX

Accurate assessment of momentum spread in electron beams is crucial for enhancing high-brightness beam injectors. A magnetic deflection-based energy analysis (EA) system is commonly employed in accelerator facilities due to its simplicity and cost-effectiveness. However, its reliance on approximation conditions, such as linear transport and no particle loss, introduces inherent errors in practical applications. This study re-examines the analytical derivation and data processing to investigate the impact of such approximations and propose reliable solutions. Through theoretical derivations and numerical simulations, the study identifies the contributions of longitudinal higher-order transport terms to measurement errors and outlines correction approaches. Furthermore, the study compares various data processing methods to assess the effects of data loss and explores suitable compensation strategies. Additionally, 1D beam dynamics are conducted, and virtual measurements are performed to validate the proposed approaches. Both theoretical and simulation results demonstrate that they effectively reduce the intrinsic errors of the EA system. • Error Source Pinpointing: Identified that the reliance on strict approximation conditions like linear transport and no particle loss in magnetic deflection-based energy analysis (EA) systems causes inherent errors. Specifically, longitudinal higher-order transport terms, especially second and third-order terms, significantly contribute to momentum spread measurement errors in electron beams for high-brightness beam injectors. • Comprehensive Methodologies: Re-examined analytical derivations and data processing methods. Employed theoretical derivations, geometric analysis, and numerical simulations to study approximation impacts. Compared various data processing methods to assess original data loss effects and developed suitable compensation strategies. • Error Reduction Validation: Conducted 1D beam dynamics simulations and virtual measurements using a developing beam diagnostic platform. Proved that the proposed methods can effectively reduce the intrinsic errors of the conventional EA system, enhancing the accuracy of momentum spread measurements for high-brightness beam injectors.