LNLS, Campinas, Brazil
SAPOTI will be the second nanoprobe to be installed at the CARNAÚBA (Coherent X-Ray Nanoprobe Beamline) beamline at the 4th-generation light source Sirius at the Brazilian Synchrotron Light Laboratory (LNLS). Working in the energy range from 2.05 to 15 keV, it has been designed for simultaneous multi-analytical X-ray techniques, including absorption, diffraction, spectroscopy, fluorescence and luminescence, and imaging in 2D and 3D. Highly-stable fully-coherent beam with monochromatic flux up to 1011ph/s/100mA-/0.01%BW and size between 35 and 140 nm is expected with an achromatic KB (Kirkpatrick-Baez) focusing optics, whereas a new in-vacuum high-dynamic cryogenic sample stage has been developed aiming at single-nanometer-resolution images via high-performance 2D mapping and tomography. This work reviews and updates the entire high-performance mechatronic design and architecture of the station, as well as the integration results of its several modules, including automation, thermal management, dynamic performance, and positioning and scanning capabilities. Commissioning at the beamline is expected in early 2024.
LNLS, Campinas, Brazil
Sirius’ long beamlines are equipped with cryogenic cooled optics to take advantage of the Silicon thermal diffusivity and expansion at those temperatures, contributing to the preservation of the beam profile. A series of improvements was evaluated from the experience in the employment of such cooling systems during the early years of operation. The main topic refers to the prevention of instabilities in the temperature of the optics due to variations in the liquid nitrogen cylinder pressure, refill automation or progressive variations of the convective coefficient into the cryostat. This work discusses the performance of these systems after optimizing the pressure of the vessels and their control logics, the effectiveness of occasional purges, cool down techniques, and presents the monitoring interface and interlock architecture. Moreover, we present the reached solution for achieving higher beam stability, considering liquid nitrogen flow active control (commercial and in-house). Also propose the approach for the future 350 mA operation, including different cooling mechanisms.
LNLS, Campinas, Brazil
CNPEM, Campinas, SP, Brazil
The SABIA beamline (Soft x-ray ABsorption spectroscopy and ImAging) will operate in a range of 100 to 2000 eV and will perform XPS, PEEM and XMCD techniques at SIRIUS/LNLS. Thermal management on these soft x-ray beamlines is particularly challenging due to the high heat loads. SABIA’s first mirror (M1) absorbs about 360 W, with a maximum power density of 0.52 W/mm², and a water-cooled mirror was designed to handle this substantial heat load. To prolong the mirror operation lifetime, often shortened on soft X-ray beamlines due to carbon deposition on the mirror optical surface, a procedure was adopted using high partial pressure of O₂ into the vacuum chamber during the commissioning phase. The internal mechanism was designed to be exactly constrained using folded leaf springs. It presents one degree of freedom for control and alignment: a rotation around the vertical axis with a motion range of about ±0.6 mrad, provided by a piezoelectric actuator and measured using vacuum compatible linear encoders. This work describes the SABIA’s M1 exactly constrained, high heat absorbent design, its safety particularities compared to SIRIUS typical mirrors, and validation tests results.
THKAM01
LNLS, Campinas, Brazil
LNLS, Campinas, Brazil
At the 4th generation synchrotron laboratory Sirius at the Brazilian Synchrotron Light Laboratory (LNLS), MOGNO is a high energy imaging beamline*, whose Nano Computed Tomography (CT) station is already in operation. The beamline’s 120x120 nm focus size, 3.1x3.1 mrad beam divergence, and 9·1011 ph/s flux at 22-67 keV energy, allows experiments with better temporal and spatial resolution than lower energy and lower stability light sources. To further utilize its potential, a new Micro CT station is under development to perform experiments with 0.5-55 um resolution, and up to 4 Hz sample rotation. To achieve this, a model of the disturbances affecting the station was developed, which comprised: i) the characterization and simulation of disturbances, such as rotation forces; and ii) the modeling of the dynamics of the Micro-station. The dynamic model was built with the in-house developed Dynamic Error Budgeting Tool**, which uses dynamic substructuring to model 6 degrees of freedom rigid body systems. This work discusses the tradeoffs between rotation-related parameters affecting the sample to optics stability and the experiment resolution in the frequency domain integrated up to 2kHz.
* N. L. Archilha, et al. 2022, J. Phys.: Conf. Ser. 2380 012123.
** R. R. Geraldes et al. 2022, Precision Engineering Vol. 77, 90-103.