A Fast Gain Calibration Algorithm for Beam Position Monitoring at Taiwan Photon Source

A stable, reliable and well-calibrated beam position monitor (BPM) system is essential for the operation of accelerators. At newly constructed Taiwan Photon Source (TPS), it not only helps us to determine the accelerator parameters, such as Twiss parameters and tune, but also to avoid the damage on accelerator instruments caused by high-energy particle beams or radiation. In this study, we demonstrate a new BPM calibration scheme at TPS storage ring. To excite the electron beams inside accelerator beam pipe by one horizontal or vertical corrector magnet, we measure the response of analog-to-digital converter (ADC) of each BPM pick-up electrodes with different lateral positions and beam currents. Depending on the measured ADC responses, we calibrated the beam position monitor system. Simultaneously, because of limited preparation time after every long shutdown, we are looking for a fast algorithm to ensure the measurement could be done easily and finished as quickly as possible.