The Elimed transport beam line

The Elimed transport beam line is constituted by a collection system, a selection system and a set of standard lenses to correct and prepare of the beam for injection into the vacuum section.
The collection system consists of 5 quadrupoles permanent magnets based on a scheme to hybrid Halbach. The lenses have a magnetic bore of 36 mm (reduced to 30 mm by a shield necessary for the protection of the permanent magnets) with a 100T / m gradient. The radial field uniformity is  better than 3%, while that longitudinal uniformity is better than 1%. The system is modular and can be adapted for the collection and optimization of references beams with different energies (3-70MeV of protons) to be injected in the next selection system. The modularity is given by the mechanism which enables to change the relative distances between the lenses and the possibility of change their polarity as well as their order.
The selection system consists of 4 resistive C-shaped dipoles (normalconductiv) that allows the selection of a single reference trajectory in chicanes. In this layout the resolving power of the system depends only on the width of selection slit (from 1 to 20 mm to obtain energy spreads from 1 up to 20%). Magnets can work with variables fields from 0.085 to 1.2T ensuring the selection for C 6 up to 70MeV / u and protons up to ~ 300MeV.
The last transport section is constituted by a set of steerer, 2 resistive quadrupoles and another steerer. The elements are designed to correct any errors of alignment of the beam (Steerers double-axis with a maximum field of ~ 300 gauss on the yoke length of 150mm) and to focus the beam before the injection in the in-air section (quadrupoles with gradient from 10T / m on a magnetic bore of 70mm diameter).