Passive correction of the persistent current effect in Nb3Sn accelerator magnets

Superconducting accelerator magnets must provide a uniform field during operation. However, the field quality significantly deteriorates due to persistent currents induced in superconducting filaments. This effect is especially large for the Nb₃Sn conductor being implemented in the next generation of accelerator magnets. A simple and inexpensive method of passive correction of the persistent current effect was developed and experimentally verified. This paper describes numerical simulations of the passive correctors and reports the test results.