ORBUMP Pulsed Dipole Magnet Design for Fermilab Booster

Fermilab initiated the accelerator magnet system upgrade project PIP-II for future neutrino experiments. Old ORBUMP pulsed dipoles should be replaced with new and stronger magnets occupying the same space as old ones. Four of these magnets connected in series form dogleg type of proton beam orbit. The magnet field and 19 kA current pulse length are close to 1 ms. Old magnet cores were based on a ferrite material. A magnet gap field above 0.4 T for new magnets completely saturates ferrite material. So, for the magnet core, 0.127 mm thick laminations of low carbon steel with inorganic coating were placed in a vacuum box. Transient magnet parameters were investigated, including the skin effect in the iron core and the single-turn copper coil. The copper coil shimming improved the integrated field homogeneity. Simulated by OPERA3D, power losses were used for the thermal analysis by ANSYS code. The magnet performance is strongly coupled with the power source. The pulsed power source design included the dynamic magnet inductance and resistance. The article presented the ORBUMP magnet system design.