Final Design of the Superferric Branched Dipoles for the FAIR Super-FRS

The superconducting fragment separator (Super-FRS) of facility for antiproton and ion research (FAIR) located in Darmstadt, Germany, requires three branched superferric dipoles which are more complex than the 21 standard dipoles already designed by Commissariat l'Energie Atomique et aux nergies alternatives (CEA). The 50-ton branched dipoles allow the beam of particles to be directed towards the different branches of the separator. The final design proposed by CEA Paris-Saclay for these dipoles integrates features required for the installation of the Y-shaped vacuum chamber which have an impact on the magnetic and mechanical design of the magnet. The coil casing design was modified and the cold-to-warm supports had to be reorganized to contain the Laplace forces acting on the weakened mechanical structure. Cryogenic experiments have been conducted to characterize the behavior of the active thermosiphon concept and to validate the cryogenic design proposed last year. We present in this paper the final design for the FAIR Super-FRS branched dipole magnets along with the design simulation results (magnetic, cryogenic, and mechanical analyses) and the main results of the active thermosiphon tests conducted recently.