Correction of the Phase Error of a Superconducting Undulator

We described a method of magnetic field correction for a superconducting undulator with neutral poles manufactured in the INP, as well as a mathematical apparatus predicting additional power currents for magnetic field correction. When correcting the field and orbit inside the undulator, the main windings of the undulator are used, grouped into separate groups and powered by additional currents. The test of this correction scheme was carried out, as well as a comparison of theoretical and experimental data of the measured magnetic field and calculated phase errors. In the SPECTRA program, the SI spectra were calculated before and after correction.