A magnetic field measurement system of superconducting quadrupole for linear accelerator

摘要

A magnetic field measurement system for superconducting quadrupoles, which are used in the cryomodule of linear accelerators, is proposed. The rotating coil and the Hall probe are used to measure the field quality of quadrupoles and the integral field strength of dipole correctors, respectively. We plan to measure this magnet in cold conditions with an accuracy: field quality of the quadrupole (represented by harmonics) within 1× 10~(-4), the integrated field of the dipole within 5 × 10~(-3), and the stray field within 1 × 10~(-5) T. In this paper, we describe the measurement system that we have designed, built, and operated. Based on the results obtained on an experiment magnet we show that this system meets all the above requirements.