Stability of off-axis motion for intense particle beams in periodically focusing channels

摘要

A general equation for the centroid motion of free, continuous, intense beamspropagating off-axis in solenoidal periodic focusing fields is derived. Thecentroid equation is found to be independent of the specific beam distributionand may exhibit unstable solutions. A new Vlasov equilibrium for off-axis beampropagation is also obtained. Properties of the equilibrium and the relevanceof centroid motion to beam confinement are discussed.