Figure 3

(A) \({B}_{y}\)-field profile along the four dipoles of the ES, as a function of the longitudinal axis z. The maximum value of \({B}_{y}\) reaches \(\sim \)0.95 T. The profile, which includes fringe fields at the edges of the dipoles, has been imported into the particle tracking code, in order to run realistic simulations of the ES. (B) Displacement of the protons in the x direction, calculated at the longitudinal position where the selecting slit is positioned, i.e. where the beam dispersion is maximum. The displacement is reported as a function of the proton energy. (C) Initial (black curve) and final (colored curves) energy spread of the proton beam as obtained with an ES having the parameters reported in Table 1. The selected energies are 2, 5, 10, 20 MeV and the final energy spread is <20% for all the cases. For this set of simulations, a collimated beam with a divergence of 3 mrad has been used, i.e. the losses induced by the collimating slit at the entrance of the ES are not taken into account, leading to an efficiency of the ES of η_ES ≈ 20%.