The BPMs are based on the interception of the tails of the photon beam transversal intensity distribution by four metallic blades collecting a drain current. The distribution has been calculated and simulated by the FERMI@Elettra Machine Physics Group, and it results Gaussian in both transverse directions. Consequently, it is possible to calculate precisely the centroid of the horizontal-vertical transverse intensity distributions. Each blade can travel 30 mm transversally, and a complete closure in both directions is possible. All the four blades are electrically insulated, and made by Copper. By reading simultaneously the four currents it is possible to determine, pulse-by-pulse, the relative displacement of each single pulse with respect to the others, and the initial nominal position. The spatial resolution is expected to be better than 2 µm rms. Moreover, by the concurrent readings of the second BPM positioned about 9 meters after, it is possible to determine the angular movement of the photon beam shot-by-shot with sub-µrad precision.

Ultima modifica il Venerdì, 15 Novembre 2019 12:07