Image charge effects in dynamics of intense off-axis beams

This paper analyzes the combined envelope-centroid dynamics of magnetically focused high intensity charged beams surrounded by conducting walls. Similarly to the case were conductingwalls are absent, we show that the envelope and centroid dynamics decouples from each other. Mismatched envelopes still decay into equilibrium with simultaneous emittance growth, but the centroid keeps oscillating with no appreciable energy loss. Some estimates are performed to analytically obtain some characteristics of halo formation seen in the full simulations.