NUMERICAL STUDY OF INTRINSIC RIPPLES IN J-PARC MAIN-RING MAGNETS

摘要

Numerical simulation results on intrinsic ripples in the J-PARC Main-ring synchrotron magnets are presented. Intrinsic ripples unavoidably arise in synchrotrons when the magnets are operated by acceleration pattern currents. The simulations are carried out with 3s and 1s of repetition cycles for the QFN magnet family, one of the typical large magnet families in the J-PARC MR. The simulated circuit is similar to the present QFN magnet system in operation with the 79Ω damping resistors. The obtained current deviation rates range in the orders of 1e-5 to 1e-3, depending on the simulated conditions. With the 1s repetition, the intrinsic ripple amplitudes increase by nearly one order compared to the 3s repetition case.