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
The mirrors for Sirius, the new 4th-generation synchrotron at the Brazilian Synchrotron Light Laboratory (LNLS), have strict requirements regarding thermo-mechanical stability and deformations, with figure height and slope errors limited to a few nanometers and tens of nanoradians, respectively. Therefore, fixed-shape mirrors have been defined with horizontally-reflecting orientation (except for vertically-reflecting mirrors of KB systems), whereas their cooling schemes (namely, air, water or liquid nitrogen cooling) depend on the particular power load. A thermal and mechanical optimization method was developed to guide the design of mirrors through the evaluation of deformations caused by power load, cooling, gravity, tightening of the fastening screws, manufacturing errors and modal analyses. Up to now, this method was already used to define the mirrors of Sirius' beamlines, which include plane, cylindrical, elliptical and ellipsoidal mirrors, as well as KB systems for microprobe and nanoprobe stations. Two examples are presented to illustrate the method.
LNLS, Campinas, Brazil
The first set of Sirius beamlines is expected to start operating in early 2019 and over the last few years many optical systems for the X-ray beamlines have been developed in-house at the Brazilian Synchrotron Light Laboratory (LNLS). Starting with the High-Dynamic Double Crystal Monochromator (HD-DCM), passing by the Double Channel-Cut Monochromator (4CM) and continuing with new standard mirror sys-tems, a series of granite benches, based on high-resolution levellers, and a combination of embedded and commercial air-bearings, has been designed for high mechanical and thermal stability. Specifications, designs, and partial results are presented, showing the progressive increase in complexity according to a deterministic design approach.