Magnets for the PETRA-III Project

The work has been carried out at the Efremov Institute according to the new PETRA-III machine optics. Normal-conducting magnets (quadrupole, dipole and corrector magnets) for the PETRA-III project were designed and calculated. Prototypes were built and magnetic measurements were carried out. Two precision quadrupole magnets with asymmetrical yoke lengths were developed. Their apertures are 70 mm and their design gradients 21.5 T/m. The integral field nonlinearity in the good field region (GFR), r_o < 25 mm should be less than 0.0005. The new dipole magnets for the PETRA-III project have a H-shaped magnetic yoke with a length of 1 m. In the GFR area of 60 mm times 36 mm a magnetic field of B_max = 1 T should be obtained. Within the GFR limits the integral field nonlinearity should be less than 0.0005, which is achieved by profiling the poles (longitudinal chamfers, slants and shims). The vertical correction dipole magnet has a horizontal magnetic field of B_X = 0.062 T, its aperture is 112 mm times 50 mm and its total length, including the coil end parts, is limited to L = 200 mm. The authors have designed two versions one with air-cooling and one with water-cooling. Results of the magnetic measurements are given and compared with the simulation