Precise isochronous field shimming using correlation matrix for compact cyclotrons

An isochronous field shimming method using pre-calculated correlation matrix was applied to the magnet shaping of a 10 MeV compact proton cyclotron. Measurement results demonstrate this method effective with high accuracy. Only after performing two iterative pole shimming procedures, ±4°±4° for history phase slip was achieved. As well as the shimming effect from measurement has a good match to the predicted value. Detailed method and experimental procedures are described.

► We proposed a high efficient matrix method for cyclotron magnet shimming.
► This method was applied to a 10 MeV compact cyclotron.
► Within two iterations, ±4°±4° of history phase slip was achieved.
► Experimental data has a good match to the prediction using this method.