Hall probe magnetic measurements of the superconducting undulator

The superconducting undulator with 15.6 mm period and 1.2 T magnetic field described in this article has 8 mm magnetic gap. The magnetic measurements system in such conditions required using of special tube (ante-chamber) inside of undulator magnetic gap. The thermal insulation between cold magnet and this measurement tube does not allow to have stable temperature along this tube length. The temperature range into this tube is 70–300 K. Hall probe measurements in this case are a rather complicated problem. The features of the method of measurement and processing of results are described.