Synchronized monochromator and insertion device energy scans at SLS

Synchronous monochromator and insertion device energy scans were implemented at the Surfaces/Interfaces:Microscopy (SIM) beamline in order to provide the users fast X‐ray magnetic dichroism studies (XMCD). A simple software control scheme is proposed based on a fast monochromator run‐time energy readback which quickly updates the insertion device requested energy during an on‐the‐fly X‐ray absorption scan (XAS). In this scheme the Plain Grating Monochromator (PGM) motion control, being much slower compared with the insertion device (APPLE‐II type undulator), acts as a “master” controlling the undulator “slave” energy position. This master‐slave software implementation exploits EPICS distributed device control over computer network and allows for a quasi‐synchronous motion control combined with data acquisition needed for the XAS or XMCD experiment.