Halbach Cylinders With Improved Field Homogeneity and Tailored Gradient Fields

We show that designs based on Halbach cylinders with a linearly increasing inner bore radius can improve the magnetic field homogeneity or can be used to tailor the spatial variation of the field gradient. We compare our first design to those based on existing methods of increasing the field homogeneity and show that it achieves a twofold improvement in the homogeneity over the next best design. We also present a second design, which can achieve a region of constant field gradient, and a third design, which can produce a region in which the product of the field and field gradient is constant