LNLS, Campinas, Brazil
Modern synchrotron light sources require high mechanical stability throughout its facilities, frequently demanding characterization processes in theμand nanometer scales. In this context, the Brazilian Synchrotron Light Laboratory (LNLS) built a new facility with several controlled environment rooms to minimize disturbances during optical and mechanical metrology procedures and to support advanced instrumentation development for the new Sirius' beamlines. The building design imposed very strict requirements regarding temperature, humidity and particles. This work presents the environmental control validation results and the floor vibration assessment enlightening the influence of the building machinery. Temperature variations below ± 0,1 °C were successfully achieved for all rooms, relative humidity is also better than 50 ± 5 % and the floor RMS displacement did not exceed 15 nm. The building is fully operational since early 2017 and currently hosting several tests on monochromators, mirrors, front-ends and many other systems for the Sirius beamlines.
Metrology, environmental control, vibration assessment
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. Naturally, the new 4th genera-tion machines, with their small emittances, start to bring higher stability performance requirements, in spite of factors as high power loads and variations, high radiation levels, ultra-high vacuum compatibility and vibration sources. In response to that, an innova-tive concept of a high-dynamic vertical DCM (Double Crystal Monochromator) with angular range between 3 and 60 degrees (equivalent to 2.3 to 38 keV with Si(111)) has been developed at the Brazilian Synchro-tron Light Laboratory. A highly repeatable dynamic system, with servo control bandwidth of 250 Hz, has been achieved and will be installed at Sirius macromo-lecular crystallography beamline ' MANACA ' still in 2018. The complete offline results of the in-vacuum cryocooled high-dynamic DCM, showing stability between crystals around 15 nrad RMS up to 2.5 kHz, even during the Bragg angle motion for flyscans, are presented.
LNLS, Campinas, Brazil
The first set of Sirius beamlines is expected to start operating in early 2019. Regarding X-ray mirror sys-tems, a single design concept has been possible thanks to the standardization of side-bounce fixed-shape mirrors. To preserve the extreme quality of both the mirror figures and the source, the main design targets were minimizing mechanical and thermal distortions in the mirrors while maximizing mechanical and thermal stabilities. A deterministic high-resolution exactly-constrained flexure-based mirror support provides pitch tuning within 100 nrad and resonances above 150 Hz, while dealing with clamping and thermal ex-pansion effects. The adopted cooling strategy was indirect cryocooling via cryostats, drastically minimiz-ing thermal gradients and distortions in the mirrors, decoupling vibration sources and simplifying cooling circuits. Finally, a 5-degree-of-freedom granite bench, based on high-resolution levellers and air-bearing solutions, support the vacuum chamber, on which the internal mechanics is stiffly mounted. The specifica-tions, design and partial results are presented.
LNLS, Campinas, Brazil
A Front End (FE) prototype for a 19-mm period length Adjustable Phase Undulator (APU19) beamline of the new Brazilian 4th-generation synchrotron, Sirius, was assembled in the LNLS metrology building in January 2017 to validate main design concepts. Regarding stability, flow-induced vibration (FIV) investigations were carried out on the water-cooled components, and modal analyses were made on the X-Ray Beam Position Monitor (XBPM) support. As for the vacuum system, final pressure levels were investigated and a vacuum breach was intentionally provoked to verify the performance of the equipment protection system (EPS). In addition, cycling tests of the Photon and Gamma shutters were conducted to verify the FE reliability. Moreover, the three-layer protection system, developed to limit the maximum aperture for the high-power slits, was functionally evaluated. Finally, the results were used to improve the FE to its final design. This paper describes the tests setups and results obtained during the validations.