TLS Fast Orbit Feedback Upgrade

Abstract

The Orbit Feedback System (OFB) at the Taiwan Light Source (TLS) was implemented two decades ago and has undergone multiple upgrades to enhance its performance. The loop bandwidth was constrained by the available hardware. The system is unable to eliminate perturbations from a fast source. In order to enhance the performance of orbit feedback, the system underwent an upgrade in 2008. The upgrade involved the replacement of the analog-type BPM electronics with digital BPM electronics, as well as the replacement of the corrector power supply with a high-performance switching-type power supply that has a wide bandwidth. Following the commissioning of the Taiwan Photon Source (TPS) in 2015, a decision was made to gradually migrate the control system of the Taiwan Light Source to the Experimental Physics and Industrial Control System (EPICS). This decision was made in order to facilitate resource sharing between the two facilities since EPICS had already been adopted by TPS. The Orbit Feedback System is a revitalized subsystem that now benefits from EPICS support. Additionally, the feedback computation unit has been upgraded to a Field Programmable Gate Array (FPGA), resulting in an increase in the calculating cycle from 2.5 kHz to 10 kHz. This report presents a concise overview of the integration of fast orbit feedback and the outcomes of the orbit stability enhancement following the upgrade.