LNLS, Campinas, Brazil
Innovative exactly-constrained thermo-mechanical de-signs for beamline X-ray mirrors have been developed since 2017 at the 4th-generation Sirius Light Source at the Brazilian Synchrotron Light Laboratory (LNLS). Due to the specific optical layouts of the beamlines, multiple systems cover a broad range of characteristics, including: power management from a few tens of mW to tens of W, via passive room-temperature operation, water cooling or indirect cryocooling using copper braids; mirror sizes ranging from 50 mm to more than 500 mm; mirrors with single or multiple optical stripes, with and without coat-ings; and internal mechanics with one or two degrees of freedom for optimized compromise between alignment features, with sub-100-nrad resolution, and high dynamic performance, with first resonances typically above 150 Hz. Currently, nearly a dozen of these in-house mirror systems is operational or in commissioning at 5 beam-lines at Sirius: MANACÁ, CATERETÊ, CARNAÚBA, EMA and IPÊ, whereas a few more are expected by the end of 2021 with the next set of the forthcoming beam-lines. This work highlights some of the design variations and describes in detail the workflow and the lessons learned in the installation of these systems, including: modal and motion validations, as well as cleaning, as-sembling, transportation, metrology, fiducialization, alignment, baking and cooling. Finally, commissioning results are shown for dynamic and thermal stabilities, and for optical performances.
|
Right click on video for Picture-in-Picture mode or Full screen display. At start the sound is muted! |
LNLS, Campinas, Brazil
CARNAÚBA (Coherent X-Ray Nanoprobe Beamline) is the longest beamline at Sirius Light Source at the Brazilian Synchrotron Light Laboratory (LNLS), working in the energy range between 2.05 and 15 keV and hosting two stations: the sub-microprobe TARUMÃ, with coherent beam size varying from 550 to 120 nm; and the nanoprobe SAPOTI, with coherent beam size varying from 150 to 30 nm. Due to the long distances from the insertion device to the stations (136 and 143 m) and the extremely small beam sizes, the mechanical stability of all opto-mechanical systems along the facility is of paramount importance. In this work we present a comprehensive set of measurements of both floor stability and modal analyses for the main components, including: two side-bounce mirror systems; the four-crystal monochromator; the Kirkpatrick-Baez (KB) focalizing optics; and the station bench and the sample stage at TARUMÃ. To complement the components analyses, we also present synchronized long-distance floor acceleration measurements that make it possible to evaluate the relative stability through different floor slabs: the accelerator slab, over which the insertion device and first mirror are installed; experimental hall slab, which accommodates the second mirror; and the slabs in satellite building, consisting of three inertial blocks lying over a common roller-compacted concrete foundation, the first with the monochromator and the remaining ones with an station each. In addition to assessing the stability across this beamline, this study benchmarks the in-house design of the recently-installed mirrors, monochromators and end-stations.