Measurements of the transverse dependence of the flux on the symmetry plane were obtained on a series of endpacks mounted on a Main Injector prototype dipole. From these flux measurements, we determined the endfield shape, expressed in terms of normal harmonics, up to 14-pole. We describe the measurement and analysis procedure, and present the results for all endpacks that were tested. The final endpack (number 10) has a sextupole, normalized to the body, of +0.167 {plus_minus} .072 units, and the relative field shape deviates by {lt} 1.2 units relative to the on-axis field strength over the range {vert_bar}x{vert_bar} {lt} 2.0{double_prime}. These measurements indicate that Endpack 10 meets the requirements for the Main Injector dipole.
