Multiturn extraction: performance analysis of old and new approaches

For some applications an intermediate extraction mode between fast (one turn) and slow (some hundreds to many billions turns) is needed. This is the case of the five-turn extraction used to transfer the proton beam from the CERN Proton Synchrotron to the Super Proton Synchrotron. The present approach is based on beam slicing via an electrostatic septum. However, recently a novel technique was proposed. By using nonlinear magnetic elements, stable islands can be generated in the transverse phase space. Furthermore, if the linear tune is varied slowly, it is possible to trap the charged particles inside the stable islands so that the beam is split into different beamlets ready for extraction. In this paper both techniques are discussed in detail with special emphasis on their robustness and the phase space matching of the extracted beam.