Abstract:

[Purpose] Ultrafast optical lasers pump-probe experiments are fundamental experimental techniques at Shanghai High Repetition rate XFEL and Extreme light facility (SHINE). Accurately determining the relative arrival time of X-ray free electron laser (XFEL) pulses with respect to the pump laser’s pulses is crucial. Logging single-pulse data with a BunchID timestamp is essential for collaborative analysis of diagnostic and experimental data. [Methods] The detector's data acquisition and control system described in this paper is built on the Experimental Physics and Industrial Control System (EPICS) framework. Detector parameters are set through a user interface developed with Python Display Manager (PyDM). The system captures image data from the pulse-arrival-time diagnostic device and incorporates the BunchID time tag from the timing system, assigning a BunchID timestamp to each image. The acquired data is stored in HDF5 format. [Results] The system is capable of real-time data acquisition from detectors and precise configuration of detector parameters, and ensures accurate alignment between detector images and BunchID. This provides essential technical support for the arrival-time diagnostic in SHINE pump-probe experiments.

Key words: XFEL, pulse arrival time diagnostic, data acquisition, EPICS, PythonSoftIOC, PyDM