Development of beam-based alignment system using a switchable shunt resistor for HLS

The development of beambased alignment system for Hefei Light Source (HLS) is presented. In this system, a switchable shunt resistor was installed on quadrupole to bypass a small percentage of the magnet current, and solid-state relays were used to switch the shunt resistor. The system can be used to measure the offset of the beam position monitor (BPM) with respect to the magnetic center of a quadrupole. Some measurement results for HLS are given.