A cylindrical coil with graduated current density for very homogeneous magnetic fields

Publisher Website
Google Scholar
Abstract
A new method of obtaining a very homogeneous magnetic field compensated to the sixth order is suggested. This is achieved by lowering the current density in the central part of a simple cylindrical coil. The optimum volume of the necessary conductor for such a coil is smaller than for a so called outer notch coil compensated to the sixth order. The new type of homogeneous coils could be very advantageous for high field superconducting solenoids. An example is given of a 6 T superconducting solenoid with an inner diameter of 3.2 cm with a field homogeneity better than 10-6 throughout a spherical volume of 1 cm diameter, which requires 10% less superconductor than a notched coil.