LNLS, Campinas, Brazil
MI-Partners, Eindhoven, The Netherlands
The monochromator is known to be one of the most critical optical elements of a synchrotron beamline, since it directly affects the beam quality with respect to energy and position. The new 4th generation machines, with emittances in the range of order of 100 pm rad, require even higher stability performances, in spite of the still conflicting factors such as high power loads, power load variation, and vibration sources. A new high-dynamics DCM (Double Crystal Monochromator) is under development at the Brazilian Synchrotron Light Laboratory for the future X-ray undulator and superbend beamlines of Sirius. Aiming at an inter-crystal stability of a few tens of nrad (even during the Bragg angle motion for flyscans) and considering the limitations of current DCM implementations, several aspects of the DCM engineering are being revisited. In order to achieve a highly repeatable dynamic system, with a servocontrol bandwidth in the range of 200 Hz to 300 Hz, solutions are proposed for a few topics, including: actuators and guides, metrology and feedback, LN2 indirect cooling, crystal clamping, thermal management and shielding. The concept of this high-dynamics DCM will be presented.
