Efficient control of accelerator maps
  Recently, the Hamiltonian Control Theory was used in [Boreux et al.] to increase the dynamic aperture of a ring particle accelerator having a localized thin sextupole magnet. In this letter, these results are extended by proving that a simplified version of the obtained general control term leads to significant improvements of the dynamic aperture of the uncontrolled model. In addition, the dynamics of flat beams based on the same accelerator model can be significantly improved by a reduced controlled term applied in only 1 degree of freedom. 
Jehan Boreux, Timoteo Carletti, Charalampos Skokos, Yannis   Papaphilippou, Michel Vittot
physics.acc-ph nlin.CD