Numerical Analysis of the Operation Parameters of Fast Cycling Superconducting Magnets

Thermodynamic Properties of Fast Ramped Superconducting Accelerator Magnets for the Fair Project

“…The losses were analysed and a two variables model (B max and f ) built, allowing predicting the required cooling power for any arbitrary cycle with sufficient accuracy. The model parameter B th shows the same behaviour as found in the FEM calculations [3] i.e. eddy currents are mainly created by the longitudinal component of the magnetic field in the magnet ends and by the transversal field component in the vacuum chamber.…”

“…We found that the linear and quadratic q h , q e can be described with sufficient accuracy for all curves with (3) with B th the threshold field (see TABLE 1). B th describes that the eddy currents are mainly created in the yoke when the ends start to saturate (also visible in the fall of the transfer functions t = B/I for the ends at around 1.2 T, FIGURE 3) and thus a field component perpendicular to the lamination is created [3] asserting that the lamination thickness does not influence the eddies for the used frequencies. The average power for an arbitrary cycle can now be calculated with the coefficients by the following procedure.…”

“…The AC losses of the magnet were measured and were found to be as predicted by FEM calculations [2,3] and by extrapolations from model magnet measurements [7]. The model magnets were built using anisotropic iron.…”

“…Thus the reduction of the cryogenic load of the SIS 100 system was a main goal of the R&D next to an improved field quality 989 [1]. Additional computational studies now allow calculating the magnetic field and AC losses matching the measurements [2,3,4]. In 2007 it was decided to build full size magnets with different coil winding technologies as well as iron yoke properties (see FIGURE 1), two straight dipoles, (Babcoeck Noell GmbH (BNG) / Würzburg: kapton insulated coil, isotropic iron yoke and JINR / Dubna: epoxy impregnated coil, anisotropic iron yoke) a curved dipole (Budker Institute for Nuclear Physics, Novosibirsk) and a quadrupole (JINR / Dubna).…”

Impact of the beam pipe design on the operation parameters of the superconducting magnets for the SIS 100 synchrotron of the FAIR project

“…Due to these many components of small dimension (compared to the total magnet length of 3m), a short end model was created enforcing dB z /dz = 0 as boundary condition, to obtain a model which can be solved within reasonable time (see Fig. 5) [20]. The central model was also used to see the impact of the different parts of the vacuum chamber on the cooling (see Fig.…”