A Novel Technique for Multi-turn Injection in a Circular Accelerator using Stable Islands in Transverse Phase Space

By applying a time-reversal to the multi-turn extraction recently proposed, a novel approach to perform multi-turn injection is described. It is based on the use of stable islands of the horizontal phase space generated by means of sextupoles and octupoles. A particle beam can be injected into stable islands of phase space, and then a slow tune variation allows merging the beam trapped inside the islands. The results of numerical simulations will be presented and discussed in details, showing how to use the proposed approach to generate hollow bunches.