How quickly the field changes across the surface, given as the steepest drop between adjacent scan points in Gauss per millimeter. A steep gradient marks a tightly focused hot spot; a gentle one means the field spreads smoothly outward.
Also known as: Gradient, Field Falloff
The field is strongest right at the coil and weakens with distance in every direction. On the on-axis dipole model the report uses, it reaches half its peak strength at about three quarters of a coil radius from center and one tenth at about two radii. A larger coil holds the field up farther out.
