Experimental control system of the X-ray magnetic circular dichroism endstation at Hefei Light Source-II.

Abstract

The Hefei Light Source-II (HLS-II) facility is undergoing upgrades to its beamline and endstation to enhance its synchrotron radiation capabilities. For the X-ray Magnetic Circular Dichroism endstation, an experimental control system leveraging Bluesky and Experimental Physics and Industrial Control System has been developed. This control system implements three distinct scan modes: step scan, fly scan and soft fly scan. The system architecture employs Queue Server for automated experiment orchestration and Ophyd based device abstraction, enabling seamless adaptation across multiple HLS-II beamlines. During software development, three key system features are included: (1) a simulation debugging environment combining a virtual server platform, virtual devices and virtual input/output controllers for closed-loop testing; (2) unified control interfaces through component abstraction; and (3) real-time data acquisition with noise-reduction methods. The implemented soft fly scan mode demonstrates particular advantages in experiments, achieving a tenfold reduction in measurement duration while maintaining signal-to-noise ratio levels comparable to conventional step scan, significantly enhancing both experimental efficiency and data quality for the user.