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  • Open Access

Arclike bunch compressor design with coherent synchrotron radiation effects

Xiuji Chen, Si Chen*, Duan Gu, and Haixiao Deng†

  • *Contact author: chens@sari.ac.cn
  • †Contact author: denghx@sari.ac.cn
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Phys. Rev. Accel. Beams 29, 104902 – Published 20 October, 2026

DOI: https://doi.org/10.1103/pn9g-7bf9

Abstract

Arclike bunch compressors are important components in recirculating accelerator linacs, energy recovery linacs, and high-brightness light sources. However, their design is complicated by longitudinal nonlinear optics and coherent synchrotron radiation (CSR), including both steady-state CSR (ss CSR) in bending magnets and CSR in the subsequent drifts (dr CSR). These effects can degrade the longitudinal compression quality, generate current spikes, and induce transverse emittance growth. In this work, we develop an analytical model for evaluating CSR effects in complex arclike compressors without relying on the small-angle approximation. The proposed method includes both ss and dr CSR contributions and is applied to the mitigation of CSR-induced transverse displacements as well as to longitudinal matching with nonlinear compression. Based on these methods, a two-stage arclike compressor using an asymmetric quadruple-bend-achromat structure is designed. Numerical simulations show that the proposed compressor can compress a 100  pC bunch to nearly 50  fs while maintaining negligible emittance growth. The analytical model is further used to study CSR-induced modifications to the compression process, including rms bunch length and peak-current behavior. Benchmarking against bmad simulations demonstrates good agreement, confirming the model as an efficient tool for compressor design and optimization.

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Phys. Rev. Accel. Beams 29, 104902– Published 20 October, 2026
  • Received 27 May 2026
  • Accepted 28 September 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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