The magnet sorting of APTRON.

The magnetic field error caused by imperfection during the manufacturing process of magnets is inevitable. Therefore, the field error of both dipole and quadrupole magnets and their alignment errors will cause the synchrotron closed orbit distortion. In order to minimize the influence of the beam, a sorting method is applied to both dipole and quadrupole magnets with integral consideration of different excitation currents, covering both low and high field situations. The commissioning result shows that we can achieve the designed beam intensity.