Beam-based alignment of injection bump magnets using remote-controlled tilt adjustment system at SPring-8

The top-up operation mode is becoming the standard operation mode in most facilities of third-generation light sources. In the top-up operation mode, it is important to keep the stored beam stable during beam injection in order for synchrotron radiation users to continue their experiments without disturbance. The injection bump magnets, however, have some alignment error in their rotation around the beam axis (tilt error), and this causes oscillation of the stored beam in the vertical direction. To suppress this oscillation, we developed a beam-based method of aligning the bump magnets using a remote-controlled tilt adjustment system. Applying the method, we could reduce the amplitude of the vertical oscillation to 0.4μm, which is approximately 1/40 of the r.m.s. beam size in the vertical direction.