Modified coherent synchrotron radiation point-kick model with self-consistent consideration of bunch length varying

Coherent synchrotron radiation (CSR) in dipoles can degrade beam quality by increasing energy spread and transverse emittance. A simple one-dimensional CSR-kick model was developed to analyze CSR effects in dipoles and derive conditions for CSR suppression [Jiao et al. Phys. Rev. ST Accel. Beams 17, 060701 (2014)10.1103/PhysRevSTAB.17.060701PRABFM1098-4402]. However, this model assumes a constant bunch length within the dipole, limiting its accuracy in scenarios involving bunch compression, where the bunch length typically varies. This limitation requires numerical corrections, which may reduce the general applicability of the model. We present a modified CSR-kick model that accounts for bunch length variations within dipoles. The modified model is validated through simulations and consistently reproduces CSR suppression conditions for double-bend achromat (DBA) compressors, showing excellent agreement with previously numerically corrected results. Further analysis of the DBA compressor under CSR suppression conditions is also provided.