This is a work-in-progress list of physical assumptions implemented in the numerics of ImpactX.
Tracking and Lattice Optics
tracking through lattice optics: is treated through linear order with respect to the reference particle
velocity spread: the above linearization implies that, when solving space-charge effects, we assume that the relative spread of velocities of particles in the beam is negligible compared to the velocity of the reference particle
Space Charge (Poisson Solver)
electrostatic in the bunch frame: we assume there are no retardation effects and we solve the Poisson equation in the bunch frame