Integrating corrector coils into quadrupole magnets offers compact steering for highcurrent ERLs, but the quadrupole yoke distorts the corrector field, especially at large transverse offsets. In PERLE’s injector/merger region the beam is space-charge dominated, and the focusing must be kept weak to limit emittance growth. This creates a balance: a tighter beam increases space-charge effects, while a wider beam enters regions where the corrector field becomes strongly nonlinear and can drive halo formation.
