Field Measurements on the Milan Superconducting Model Magnet

As a whole, we believe that, as far as magnetic field properties are concerned, the following conclusions can be drawn with a large degree of assurance: i) azimuthal field modulation, as calculated from any saturated pole tip geometry, agrees with data to such an extent that this method can safely be used to predict harmonic amplitudes and phases; ii) absolute values of the average magnetic field can be predicted, even with a rather rough approximation, to within ± 1.%, at least in the range of fields B ¿ 25 kG where pole iron is largely saturated. This holds for inner radii fields and fri ngi ng fi el ds as wel 1; iii) more refined and time-consuming calculations can probably trim down these errors to a few parts per thousand, although, in our belief, with little more advantage from the point of view of a cyclotron early design. As quoted above, all magnetic field measurements stopped in January 1978. They will resume only if the cyclotron will be built, this time with the precise purpose of designing the final iron geometry of the machine. We believe that the availability of the model will enable us to shorten considerably the time needed to define, down to the very last details, the overall structure of the cyclotron.