Effects of Nonlinear Decoherence on Halo Formation
  High intensity proton linacs and storage rings are central for the development of advanced neutron sources, extending the intensity frontier in high energy physics, as drivers for the production of pions in neutrino factories or muon colliders, and for the transmutation of radioactive waste. Such high intensity beams are not attainable using conventional linear lattices. It has been shown in the single particle limit that integrable nonlinear lattices permit much larger tune spreads than conventional linear lattices, which would mitigate many of the space charge restrictions that limit intensity. In this paper, we present numerical studies of space charge effects on a trial nonlinear lattice with intense bunches. We observe that these nonlinear lattices and their accompanying tune spreads strongly mitigate halo formation using a result from the particle-core model known to cause halo formation in linear lattices. 
Stephen D. Webb, David L. Bruhwiler, Dan T. Abell, Andrei Sishlo,   Viatcheslav Danilov, Sergei Nagaitsev, Alexander Valishe...
physics.acc-ph nlin.SI physics.class-ph