New coil end design for the RHIC arc dipole

The racetrack-shaped coils for the RHIC arc dipoles are wound with 32 turns of flat cable interleaved in the curved ends with insulating material {“spacers”} of varying thickness. To simplify production, the number of spacers, about 64 in each coil end, was reduced by making some of them thicker, to about 23. A new computer program was written which gives a description of each turn closely resembling the turn as made. The output of this program is processed by newly written computer programs which change the parts descriptions into forms which are used by a computer-controlled, 5-axis milling machine. The solid spacers replace spacers assembled from laminations and improve the fit as well. The parts will be molded during production. The calculated harmonic content of the ends is compared with measurements on the first magnets built with the new ends