Transmissive Imaging X-Ray Beam Position Monitors (XBPM) for Protein Crystallography (PX) Beamlines

摘要

We present the development of transmissive imaging X-ray Beam Position Monitors (XBPM) for use in Protein Crystallography (PX) beamlines and beamlines operating at photon energies around and above 10 keV and fluxes of 1010 photons/s or higher. Results from different phosphors, substrates and coating techniques are compared with respect to transmission, layer quality and image resolution. The screen absorption is below 10 % for selected phosphors at photon energies above 10 keV. This enables continuous monitoring of both beam shape and intensity during experimental data collection at a few micron resolution. The screens have been designed for monochromatic beams, with a maximum beam diameter of 2 mm (extendible to 25 mm). The presented approach not only promises a generic solution for use in the automation of PX beamlines, but will also be extendible to other state-of-the-art crystal monochromator beamlines.