The SHERPA project aim is to develop an efficient technique to extract a positron beam from one of the accelerator rings composing the DAFNE complex at the Frascati National Laboratory of INFN, setting up a new beam line able to deliver positron spills of O(ms) length, excellent beam energy spread and emittance. The most common approach to slowly extract from a ring is to increase betatron oscillations approaching a tune resonance in order to gradually eject particles from the circulating beam. SHERPA proposes a paradigm change using coherent processes in bent crystals to kick out positrons from the ring, a cheaper and less complex alternative. A description of this innovative non-resonant extraction technique is reported in this manuscript, including its performance preliminary estimation.
@article{arxiv.2110.02816,
title = {Crystal slow extraction of positrons from DAFNE: the SHERPA project},
author = {M. Garattini and D. Annucci and O. R. Blanco-Garcia and P. Gianotti and S. Guiducci and A. Liedl and M. Raggi and P. Valente},
journal= {arXiv preprint arXiv:2110.02816},
year = {2021}
}