Magnetic field full test of two-section KIAE-4 undulator

Two-sections of the KIAE-4 undulator have been assembled and the magnetic field has been finally tuned. Special attention was paid to focusing strength adjustments in both sections. To obtain this rather strong focusing in both transverse directions a combined focusing scheme was used. Field matching in the intersection gap was controlled using the first and the second integrals of the magnetic field along the entire undulator length. The results of the full test of the undulator have demonstrated a high accuracy of the magnetic field obtained, a wide range of the focusing strength tunability along with a high sensitivity of the electron beam optics to the intersection magnetic field.