Implementation and test of a synchrotron radiation position monitor at a user beam line

A slotted plate photodiode beam position monitor was built and installed on a user beam line. The detector is positioned in front of the first optical component of the beam line intercepting ∼3 mrad of synchrotron radiation. A 25‐μm‐thick Be foil strongly attenuates photons with hν<800 eV and improves the position sensitivity by reducing the vertical angular divergence of the effective photon beam by more than a factor of 10. With a 125‐μm gap at 45° angle between the diode plates, the detector has a linear working range of ∼±800 μm. The vertical position sensitivity of the beam position monitor is ∼5 μm.