Application of Energy Storage System for Stabilization of Accelerator Magnet Power Supply

Magnets of the synchrotron which extracts the accelerated beams are excited by a pulse operation power supply, and then the load fluctuation should be a severe problem. An energy storage system, such as superconducting magnetic energy storage (SMES), fly-wheel generator so far, will be required for compensating the pulse electric power, and reducing the disturbances of the connected power line. The system is expected to protect the instantaneous voltage drop and the load fluctuation. Present status of R & D and the features for the energy storage systems are discussed. The application of the energy storage systems to synchrotrons for the medical use is described. The compensation of the typical pulse electric power of the synchrotron for the cancer therapy is studied, and the operation cost saving and the cost performance of the SMES system are discussed.