The Superconducting Coil

The CLEO II superconducting coil provides a uniform 1.5 Tesla magnetic field parallel to the beam line over the full volume of the inner tracking, time-of-flight, and calorimetry systems.

The coil was designed and built by Oxford Instruments, Ltd., and delivered to Cornell in July of 1987. It has an inner diameter of 2.9 meters, and the coil is 3.5 meters in length. The coil itself is wound from 5 mm x 16 mm aluminum stabilized superconductor, which is cooled by a liquid helium refrigeration system, utilizing the stable, self-regulating thermosyphon circulation flow system.

Shown here is the CLEO II detector about halfway through the assembly process. The outer surfaces in the photograph are the first few layers of iron shielding, and the stainless container on top of the detector is a liquid helium storage dewar and instrument pack.

The magnet yoke, pole pieces, and flux return system are also used as part of the shielding for the muon tracking chambers.