Superconducting Magnet Models for Isabelle

The development program for the superconducting magnets of the Intersecting Storage Accelerators is described. The dipole magnet design is of the cos ¿ type and employs wide ribbon conductor. Magnetic measurements are compared with calculations which include the effects of conductor magnetization and iron saturation. Calculations of the harmonics due to the magnet ends will also be presented along with estimates of the effect of the shape of the outer boundary of the iron shield on the field and the degree of interaction between the magnets in the two rings. The conductor is a metal-filled braid woven from 186 wires each containing 400 filaments. A precision molding technique has been developed which assures accurate placement of the turns and could be used for semi-mass production. The iron cores are laminated and assembled in a special way to eliminate the axial differential expansion between the coil and the core. Correction coils for the 3¿ and 5¿ terms are built into the bore tubes. These coils are necessary to correct the small (10-3) harmonics produced by conductor magnetization at low field and iron saturation at high fields.