Commissioning of the cryogenic sample environment for the TARUMÃ station at the CARNAÚBA beamline at Sirius/LNLS

Abstract

TARUMÃ is a multi-technique station at CARNAÚBA (Coherent X-Ray Nanoprobe Beamline) at the 4th-generation light source Sirius at the Brazilian Synchrotron Light Laboratory (LNLS). With a tender-to-hard energy range from 2.05 to 15 keV and a fully coherent nanoprobe focused via an all-achromatic KB (Kirkpatrick-Baez) optics, it can be used for simultaneous multiple nanoscale X-ray techniques in 2D and 3D. This includes ptychography coherent diffraction imaging (ptycho-CDI), absorption spectroscopy (XAS), diffraction (XRD), fluorescence (XRF) and luminescence (XEOL). In particular, the tender energies can be used to study light elements that are commonly present in soft biological samples, ensuring the unique position of the station in the Life and Environmental Sciences program at LNLS. Still, enabling this range of experiments is sometimes only possible with cryogenically cooled samples as the high beam dose can result in both chemical and structural damage at ambient temperature conditions. At TARUMÃ, to comply with the heavily occupied volume around the sample and the sample positioning architecture, this is enabled by an open-atmosphere cryogenic system based on a commercial cryojet and a custom-designed sample holder. Following a predictive engineering approach, the system is capable of conditioning the sample down to 155K, whilst avoiding icing and condensation in nearby instrumentation and preserving the nanometer-level positioning requirements of the scanning station. Here we present the commissioning results of the referred system along with the first beamline measurements.