Speaker
Description
The Fixed-Field Alternating-Gradient (FFA) accelerator achieves strong-focusing acceleration over a wide energy range with fixed magnetic fields. However, magnet field errors and alignment deviations persist over the full momentum range, causing cumulative beam quality degradation through energy-dependent closed orbits. This study focuses on the spiral-type FFA accelerator at the China Spallation Neutron Source (CSNS), systematically evaluating static magnet error effects and exploring correction schemes. A mathematical model incorporating dipole, quadrupole, spiral angle, and fringe field errors, as well as misalignment and rotation errors, is established. Combined simulations using PyZgoubi and PyFFA are performed with 100 random seeds for statistical analysis and single-error scanning. The error effects exhibit notable energy dependence, imposing multi-energy constraints on trim coil design. Preliminary correction strategies based on main field adjustment and trim coils are discussed, providing simulation references for magnet fabrication, alignment, and correction system design of the CSNS-FFA.