The Construction of the Model of the Curved Fast Ramped Superconducting Dipole for FAIR SIS300 Synchrotron

The Facility for Anti-proton and Ion Research (FAIR), under development at GSI, includes the synchrotron SIS300, so called because the magnetic rigidity is 300 Tm. In order to reach the required high intensities of proton and heavy ions beams, the bending dipole magnets have to be pulsed from the injection magnetic field of 1.5 T up to 4.5 T maximum field at the rate of 1 T/s. These 7.8 m long magnets have cos θ shaped coils with a 100 mm bore and the particular characteristic to be geometrically curved, with a sagitta of 112.9 mm. These challenging requirements triggered R&D activities, aimed at the development of suitable construction technologies for fast ramped curved coils. The heart of the R&D program is the construction of a 3.9 m long model. The paper discusses the main problems faced during the design and the construction of the cold mass, mainly covering the aspects related to the manufacture.