Synchronized and repetitive control of the main magnet power supply for accelerators

In order to realize the accelerators having good performance, it becomes the premise that the accuracy of magnetic fields generated with electromagnets is high. In the proton and heavy particle beam synchrotrons for medical treatment, in order to reduce beam loss, the especially good accuracy of magnetic fields is required. The operation of changing to the optimal beam energy and kind of particles for the diversified objects of treatment is carried out frequently, accordingly, in order to improve the rate of operation, the adjustment of tracking for obtaining the operation pattern of good accuracy must be easy. The synchronized repetitive control system for the power supply of accelerator magnets was developed and applied to the HIMAC. The synchronized control of synchrotrons is explained. The objective of repetitive control is to automatically form the voltage pattern required for realizing the prescribed current pattern. The automatic correction of voltage pattern by repetitive control is shown. The results of the synchronized repetitive control test for the power supply of magnets are reported, and the accuracy was able to be improved by this control to about 8 x 10-4. (K.I.)