The HD-DCM-Lite: A High-Dynamic DCM with Extended Scanning Capabilities for Sirius/LNLS Beamlines
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A.V. Perna, H.O.C. Duarte, R.R. Geraldes, M.A.L. Moraes, M. Saveri Silva, M.S. Souza, G.S. de Albuquerque
LNLS, Campinas, Brazil
Funding:Ministry of Science, Technology and Innovation (MCTI) After successfully designing, installing, and commissioning two units of the High-Dynamic Double-Crystal Monochromator (HD-DCM) at the Brazilian Synchrotron Light Laboratory (LNLS) - Sirius, two more units are now required. Since they demand only a smaller energy range (5 to 35 keV), the total gap stroke of the new instruments can be significantly reduced, creating an opportunity to adapt the existing design towards the so-called HD-DCM-Lite. Removing the large gap adjustment mechanism allows a reduction of the main inertia by a factor of 5, enabling the HD-DCM-Lite to deliver energy flyscans of hundreds of eV reaching 20 cycles per second while keeping fixed exit and the pitch stability in the range of 10 nrad RMS (1 Hz - 2.5 kHz). Hence, an unparallel bridge between slow step-scan DCMs and fast channel-cut monochromators is created. This work presents the in-house development of the HD-DCM-Lite, focusing on its mechanical design, discussions on the ultimate scanning constraints (rotary stage torque, voice-coil forces, interferometers and encoders readout speed limits and subdivisional errors), and thermal management.
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