Field measurement results of the KEK B-factory quadrupole and sextupole magnets

The magnetic properties of the quadrupole and sextupole magnets for the KEK B-factory rings (LER and HER) are measured by two sets of harmonic coil systems, one for the LER magnets and the other for the HER magnets, at KEK over an 18 month period. The main field strength, offsets between the mechanical and magnetic centers, higher order multipole components and effective lengths of the magnets are measured.