Magnetic Field Measurement of Superconducting Dipolemagnets with Harmonic Coil and Hall Probe

Abstract

Magnetic field measurements and field analyses of 1-m long superconducting dipole magnets fabricated at the National Laboratory for High Energy Physics (KEK) have been carried out using a harmonic coil with the bucking scheme.¹ Conditions of the data acquisition are optimized to achieve the accurate and efficient measurements. Not only in the steady state of the magnet excitation by constant currents, but also on the way the excite current increases until the magnet quenches the field measurements have been tried, and the results are discussed in this paper on the possibility of the “on-the-fly” measurement using a harmonic coil. Some results on the so-called remnant field of the magnets measured with a Hall probe are also described.