Orbital Beam Dynamics in Multipole Fields via Multiscale Expansions

We present the applications of methods from nonlinear local harmonic analysis in variational framework to calculations of nonlinear motions in polynomial/rational approximations (up to any order) of arbitrary n-pole fields. Our approach is based on the methods provided possibility to work with dynamical beam/particle localization in phase space, which gives representions via exact nonlinear high-localized eigenmodes expansions and allows to control contribution to motion from each scale of underlying multiscale structure.