17–22 May 2026
C.I.D
Europe/Zurich timezone

Optimizing Momentum Aperture in Korea-4GSR via Higher-Order Chromaticity and W-function Analyses

SUP5605
17 May 2026, 14:00
4h
C.I.D

C.I.D

Poster Presentation MC5.D02: Nonlinear Single Particle Dynamics Resonances, Tracking, Higher Order, Dynamic Aperture, Code Developments Student poster session

Speaker

Junha Kim (Pohang Accelerator Laboratory, Ulsan National Institute of Science and Technology)

Description

Recent upgrades of synchrotron light sources aim to achieve ultralow emittances, requiring strong magnet strengths that inevitably lead to severe nonlinear effects. Consequently, securing a sufficient Touschek lifetime has become a critical challenge for storage rings, including the Korea-4GSR. In this study, we performed systematic scans of tune and chromaticity to identify optimal working points and characterize lattice properties in the presence of nonlinearities and errors. Through these scans, we observed a distinct dependency of the Touschek lifetime on chromaticity settings. We explain the reason for the optimal chromaticity range by analyzing Momentum-Dependent Tune Shift (MDTS) curves and higher-order chromaticity effects.
Nonetheless, directly optimizing the lifetime is computationally intensive because it requires calculating the momentum aperture along the entire ring. Hence, to overcome this challenge, we propose an efficient indirect optimization method based on the analysis of W-function fluctuations.

In which format do you inted to submit your paper? LaTeX

Author

Junha Kim (Pohang Accelerator Laboratory, Ulsan National Institute of Science and Technology)

Co-authors

Dr Jaehyun Kim (Pohang Accelerator Laboratory) Gyeongsu Jang (Pohang University of Science and Technology) Jimin Seok (Pohang Accelerator Laboratory) Jaeyu Lee (Pohang Accelerator Laboratory) Prof. Moses Chung (Pohang University of Science and Technology)

Presentation materials

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