Design of 30 T split-pair pulse coils for LANSCE

The NHMFL has designed a high-frequency split-pair coil system for the Los Alamos Neutron Science Center (LANSCE) that can achieve fields up to 30 T for greater than 10/sup 5/ cycles and up to 26 T for 10/sup 7/ cycles in a 20 mm bore and a 5 mm clear split at the midplane. The magnet system pushes the limits of the technology by requiring a clear split, except for 14 mm of aluminum, and a 2 Hz pulse frequency. The 14 mm of aluminum is in the form of rings required to help support the 1337 kN magnetic load between the two coil halves. The clear split allows the neutrons to travel unobstructed from source to detector. The 2 Hz pulse frequency requires that the coils be continuously cooled with de-ionized water flowing at 15 m/s along the inner diameters of each coil. This paper summarizes the overall design, discusses some of the key features and predicts the coil fatigue performance based on available conductor fatigue properties. The coils are presently being fabricated and scheduled for delivery to the LANSCE in early 2000.