| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1831655 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2007 | 6 Pages |
With the Beijing Electron Positron Collider upgrade project (BEPC-II), two dual-aperture septum-style quadrupole magnets are used in the interaction region for the final focusing of the electron and positron beams. The BEPC-II lattice design calls for the same high quality integral quadrupole field and large good field region in both apertures for each magnet. Two-dimensional contour optimization and pole-end chamfer iteration are used to minimize the systematic harmonic errors. Unexpected non-systematic errors induced by the unsymmetrical structure and the manufacturing errors are compensated with the pole-end shimming. Magnet measurements with rotating coils are performed to guide and confirm the magnet design. This paper discusses the design consideration, optimizing procedure and measurement results of these dual-aperture magnets.
