Methods of measurement for the beam-based alignment System in HLS

摘要

The beam-based alignment system is given in HLS (Hefei Light Source), in which a switchable shunt resistorwas installed on quadrupole to bypass a small percentage of the magnet current. The system can measureBPM-to-quadrupole offset which can be used to position the beam in the magnetic center of quadrupoles. In measurement,some methods ( linear fitting with single corrector, parabola fitting with single corrector, linear fitting withlocal bump, and parabola fitting with local bump ) are used. These measurement results are given, and comparedamong the methods mentioned above.