LNLS, Campinas, Brazil
CNPEM, Campinas, SP, Brazil
Sirius, the Brazilian 4th-generation light source at the Brazilian Synchrotron Light Laboratory (LNLS), presents high-performance requirements in terms of preserving photon-beam quality, particularly regarding wavefront integrity and position stability. In this context, it is imperative that many silicon optical elements* be effectively cooled, such that temperatures and their control-related parameters can be precisely handled to the point in which thermal effects are acceptable concerning figure distortions and drifts at different timescales. For this class of precision equipment, the required performance can only be achieved with robust thermal management.** For this, relevant aspects related to the implementation of liquid nitrogen cooling systems need to be emphasized. Currently, two solutions are present at the first-phase beamlines, according to the component thermal load: (1) an in-house low-cost system for components under moderate loads (< 50 W), such as the mirror systems and the four-bounce monochromators, comprising a commercial cryostat connected to an instrumented vessel, whose level and pressure are controlled by the standard beamline automation system that can automatically feed it from a secondary service unit or a dedicated transfer line; (2) a commercial cryocooler for high-heat-load applications (50 - 3000 W), such as the double-crystal monochromators. This work presents the in-house solution: requirements, design aspects, operation range, as well as several discoveries and improvements deployed during the commissioning of the CATERETÊ and the CARNAÚBA beamlines, such as the prevention of ice formation, stabilization of both thermal load and flow-rate, and auto-filling parameters, among others.
*TOLENTINO. Innovative instruments (…) for the CARNAÚBA beamline at Sirius-LNLS. SRI (2018).
**VOLPE. Performance validation of the thermal model for optical components. Submit to MEDSI (2020)
LNLS, Campinas, Brazil
CNPEM, Campinas, SP, Brazil
Beamlines of new 4th-generation machines present high-performance requirements in terms of preserving beam quality, in particular wavefront integrity and position stability at micro and nanoprobe stations. It brings about numerous efforts to cope with engineering challenges comprehending high thermal load, cooling strategy, crystal manufacturing, vibration sources, alignment and coupled motion control. This contribution presents the design and performance of a four-bounce silicon-crystal monochromator for the Sirius beamlines at the Brazilian Synchrotron Light Source (LNLS), which is basically composed of two channel-cut crystals mounted on two goniometers that counter-rotate synchronously. The mechanical design ascertained the demands for the nanoprobe and coherent scattering beamlines - namely, CARNAÚBA and CATERETÊ - focusing on solutions to minimize misalignments among the parts, to grant high stiffness and to ensure that the thermal performance would not impair beam characteristics. Hence, all parts were carefully simulated, machined, and measured before assembling. This work details mechanical, thermal, diagnostics, and dynamic aspects of the instruments, from the design phase to their installation and initial commissioning at the beamlines.
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.
LNLS, Campinas, Brazil
TARUMÃ is the sub-microprobe station of the CARNAÚBA (Coherent X-Ray Nanoprobe Beamline) beamline at Sirius Light Source at the Brazilian Synchrotron Light Laboratory (LNLS). It has been designed to allow for simultaneous multi-analytical X-ray techniques, including diffraction, spectroscopy, fluorescence and luminescence and imaging, both in 2D and 3D. Covering the energy range from 2.05 to 15 keV, the fully-coherent monochromatic beam size varies from 550 to 120 nm after the achromatic KB (Kirkpatrick-Baez) focusing optics, granting a flux of up to 1e11ph/s/100mA at the probe for high-throughput experiments with flyscans. In addition to the multiple techniques available at TARUMÃ, the large working distance of 440 mm after the ultra-high vacuum (UHV) KB system allows for another key aspect of this station, namely, a broad range of decoupled and independent sample environments. Indeed, exchangeable modular setups outside vacuum allow for in situ, in operando, cryogenic and/or in vivo experiments, covering research areas in biology, chemistry, physics, geophysics, agriculture, environment and energy, to name a few. An extensive systemic approach, heavily based on precision engineering concepts and predictive design, has been adopted for first-time-right development, effectively achieving altogether: the alignment and stability requirements of the large KB mirrors with respect to the beam and to the sample*; and the nanometer-level positioning, flyscan, tomographic and setup modularity requirements of the samples. This work presents the overall station architecture, the key aspects of its main components, and the first commissioning results.
* G.B.Z.L. Moreno et al. "Exactly constrained KB Mirrors for Sirius/LNLS Beamlines: Design and Commissioning of the TARUMÃ Station Nanofocusing Optics at the CARNAÚBA Beamline", presented at MEDSI’20, paper TUOB01, this conference.
LNLS, Campinas, Brazil
TARUMÃ is the sub-microprobe station of CAR-NAÚBA (Coherent X-Ray Nanoprobe Beamline) at Sirius at the Brazilian Synchrotron Light Laboratory (LNLS). Covering the tender-to-hard energy range from 2.05 to 15 keV with achromatic fixed-shape optics, the fully coherent submicron focused beam can be used for multiple simultaneous advancedμand nanoscale X-ray techniques that include ptychography coherent diffraction imaging (ptycho-CDI), absorption spectroscopy (XAS), diffraction (XRD), fluorescence (XRF) and luminescence (XEOL). Among the broad range of materials of interest, studies of light elements present in soft tissues and other biological systems put TARUMÃ in a unique position in the Life and Environmental Sciences program at LNLS. Yet, to mitigate the detrimental effect of the high photon flux of the focused beam due to radiation damage, cryocooling may be required. Here we present the design and first results of a novel open-atmosphere cryogenic system for online sample conditioning down to 110 K. The high-stiffness and thermally-stable sample holder follows the predictive design approach based on precision engineering principles to preserve the nanometer-level positioning requirements, whereas a commercial nitrogen blower is used with a cold gas flow exhaustion system that has been developed in order to avoid unwanted cooling of surrounding parts and water condensation or icing.
LNLS, Campinas, Brazil
UNICAMP, Campinas, São Paulo, Brazil
CARNAÚBA (Coherent X-Ray Nanoprobe Beamline) is a state-of-the-art multi-technique beamline at the 4th-generation Sirius Light Source at the Brazilian Synchrotron Light Laboratory (LNLS), with achromatic optics and fully-coherent X-ray beam in the energy range between 2.05 and 15 keV. At the TARUMÃ station, the in-vacuum KB focusing system has been designed with a large working distance of 440 mm, allowing for a broad range of independent sample environments to be developed in open atmosphere to benefit from the spot size between 550 to 120 nm with a flux in the order of 1e11 ph/s/100mA. Hence, together with a number of different detectors that can be simultaneously used, a wide variety of studies of organic and inorganic materials and systems are possible using cutting-edge X-ray-based techniques in theμand nanoscale, including coherent diffractive imaging (CDI), fluorescence (XRF), optical luminescence (XEOL), absorption spectroscopy (XAS), and diffraction (XRD). Even though samples over the centimeter range can be taken at Tarumã, the small beam and relatively low energies point towards optimized and reduced-size sample holders for in situ experiments. This work describes two related setups that have been developed in-house: a small-volume electrochemical cell with static fluid*; and another multifunctional environment that can be used both as a microfluidic device and as an electrochemistry cell that allows for fluid control over samples deposited on a working electrode. The mechanical design of the devices, as well as the architecture for the fluid and electrical supply systems, according to the precision engineering concepts required for nanopositioning performance, are described in details.
*Vicente, Rafael A., et al., "Bragg Coherent Diffraction Imaging for In Situ Studies in Electrocatalysis," ACS nano (2021).