Superconducting (SC) multiplets are a key component for the Super-FRS facility together with the superconducting main dipole magnets. Because the secondary beam generated at the target has very high energy and the momentum phase space is largely populated, magnets with a large acceptance aperture are necessary. Therefore, a superferric magnet design has been adopted for most of the Super-FRS magnets, except the few ones placed close to the target area, where the radiation level is very high.

Thirty multiplets will be deployed along the beam line. In these multiplets, quadrupole magnets and corrector magnets, such as sextupole magnets, octupole magnets, and steering dipole magnets, are assembled as a single cold mass column. The magnets will be cooled in a common liquid helium bath at 4.5 K. The design pressure of the helium vessel is 20 bar, allowing it to withstand any pressure increases that may occur in the event of a magnet quench. While the dipole magnets steer the beams, the quadrupole magnets focus the beam, and the corrector magnets adjust the beam path. There are twenty-three different types of cryogenic modules where the cold mass is composed of a different number of quadrupole and corrector magnets, depending on space constraints and beam optical requirements. The production of the magnets and their cryogenic testing are progressing at our supplier in Italy and at CERN, respectively.

Some key facts about the multiplets are as follows:

• The magnetic fields of the quadrupole and the sextupole magnets are shaped by their yokes (iron-dominated magnet)
• The magnets (iron yokes and coils) are cooled in the helium bath at 4.5 K
• Good field region is 190 mm and the warm bore diameter is 384 mm
• Niobium-titanium superconductor racetrack coils are used for the quadrupole and sextupole magnets
• The steering dipole magnets and the octupole magnets are cos-theta magnets
• The largest multiplet, consisting of nine magnets, weighs approximately 65 tons and their length is about 7 m

If you want to know more details please do not hesitate to write us. Here you will find all contacts.