Physical viability of near-source scattering during magnetospheric PA evolution

Establish whether the physical conditions required for scattering to occur while the polarisation angle is still evolving in a neutron-star magnetosphere can be realised, including the production of millisecond-scale delays by scattering material that remains coupled to the region responsible for the polarisation-angle evolution.

Background

The persistence of a coherent polarisation-angle swing through the scattering tail of FRB 20250607A is difficult to reconcile with a simple scattering model. One proposed explanation is that scattering occurs within the near-source magnetospheric environment while the polarisation state is still changing, but the paper treats this scenario as speculative because it requires the scattering material to remain physically coupled to the polarisation-evolution region while producing millisecond-scale delays.