The Q1, Q2 and D magnets will be tested and their magnetic fields are to be mapped at the factory of the manufacturing company. Three dimensional field distribution will be measured with an automatic 3D mapping system for each magnet. It is also planned to examine interference of the three magnets, since they are placed very close to each other and the interference could be a problem for a high resolution spectrometer. The interference effects between magnets was evaluated to some extent with the TOSCA 3D field calculation program which showed shortening of the effective field boundaries of the Q1 and Q2 magnets. It is, thus, necessary to examine the interference experimentally.
In this way, thorough field measurement of the HKS magnets will be carried out before they are shipped to Jlab. At Jlab, the field measurement will be performed at several points to check whether the result in Japan is reproduced in order to confirm the accuracy of the assembly.