Closed feedback system on the vertical beam position

Abstract

We have developed two feedback systems to keep constant the vertical position of the incident beam on a sample. They are systems enclosed within the experimental station and independent of the storage ring. The first system adjusts the sample height by translating an apparatus in the case where the shortest response speed of feedback was about 0.5 s. The variation of the beam height was stabilized within about 5 μm. The other system changes the distance between two crystals of a double-crystal monochromator. The height of the exit beam was stabilized within 10 μm against any fluctuation of the incident beam.