An electronic cam control technology for maintaining the output beam height from a symmetrical layout type double crystal monochromator

Abstract A new electronic cam control system has been developed for a symmetrical layout double crystal monochromator, incorporating PID control with encoder feedback. The system improves the stability of the exit beam height over a wide Bragg angle range (7.3°–70.0°), achieving an accuracy of ±1.0 μm, as validated at BL10U, NanoTerasu. It also supports high-speed scanning at 1.0°/sec. Compared to the previous model, the updated system reduces relative height variation by half, while enabling faster scanning speeds and greater angular ranges. Future developments will focus on beam offset adjustability and automatic parallelism correction.