Full-Scale ISA Dipoles

After the life test of the two 8-cm (diameter) aperture one-meter long magnets (ISA I and II) had been satisfactorily concluded, the next logical step is the construction of a full-scale (12-cm aperture 4.25-meter long) dipole. The 12-cm magnet is essentially a larger version of ISA I and II with the exceptions of conductor and structural material refinements that have evolved in the 5 and 8-cm aperture model magnet series and comparable programs in other laboratories. The magnet windings will have a 23% higher packing density than ISA I and II. The rate of magnetic field sweep at which the magnetization of the magnet doubles, is an order of magnitude faster, due to improved conductor geometry. The peak magnetic field is approximately 5% greater than the central field 'B(0,0)' in the new design which has 85% usable aperture (≈ 67% actually required). The design field 'B(0,0)' is 4.0 T at 4.5 °K. The coil parameters are ID = 12.05 cm, OD = 15.538 cm, length = 427 cm and 80 turns/pole. The magnet is presently under construction and only prototype data and computed characteristics are presently available.