Design and construction of a 5 T 1028 mm bore magnetic resonance imaging (MRI) magnet

New York Neurological Institute of Columbia University, requires a 5 T 1028 mm bore MRI magnet for brain function imaging and spectroscopy use. The magnet has a persistency of about 3/spl times/10/sup -8//hr, a field uniformity of 0.4 ppm over 40 cm DSV and a liquid helium boil off of 0.55 litres per hour. In order to achieve good field uniformity, 12th order field uniformity coil windings was constructed. In addition, 18 sets of superconducting shim coils are built for field correction. The magnet weighs 26 tons. Design and construction will be described. >