Predictive modeling through Dynamic Error Budgeting applied to the High-Dynamic Double-Crystal Monochromator for Sirius light source

Abstract

To address recent and more stringent nanometer-level requirements in positioning stability, the High-Dynamic Double-Crystal Monochromator (HD-DCM) has been in development since 2015 for X-ray beamlines of Sirius, the 4th-generation light source at the Brazilian Synchrotron Light Laboratory (LNLS). The unprecedented 10 nrad RMS (1Hz-2.5 kHz) inter-crystal parallelism in fixed and scanning modes represents improvements by factors of 5 and 100 with respect to state-of-the-art DCMs, respectively — which became possible only due to its innovative isolated mechatronic architecture with high closed-loop performance, rigorous precision engineering principles, and predictive design via Dynamic Error Budgeting (DEB). This work demonstrates the DEB methodology applied to the HD-DCM via a three-dimensional-space mechatronic model based on a lumped-mass system of 11 rigid bodies. Special attention is given to the disturbance models based on measurements and to performance prediction in fixed-energy operation mode, which is finally compared with experimental results in the real system. Hence, this article presents the step-by-step predictive modeling process of the HD-DCM as a successful case study on the efficient development of innovative high-performance mechatronic machines, which could be a game changer in synchrotron beamline instrumentation.