Effect of Surface Strains on the Diamagnetic and Field-Retaining Properties of Type-i Hollow Cylinders

High-purity hollow cylinders of type-I superconductors in which the surface strains are minimal show order-of-magnitude decreases from the diamagnetic or field trapping properties described in present literature. The properties can be made to approach the predicted behavior when both surfaces are heavily strained. Both the diamagnetic and field-retaining properties are localized and can result in axial-field gradients in the void that exceed ${10}^3$ Oe/cm.