Speaker
Description
Following the shutdown of ELETTRA, the former Austrian Small Angle X-ray Scattering (SAXS) beamline will be replaced by two new SAXS beamlines at the low-emittance storage ring ELETTRA 2.0, the upgrade program of Elettra Sincrotrone Trieste: the high-flux (HF) and high-brilliance (HB) SAXS beamlines.
This contribution presents the main design parameters and scientific case. The HF-SAXS beamline uses a 1.4 m long, 49-pole superconducting wiggler (3.5 T), accepting a radiation cone of 0.2 × 0.5 mrad at 0.75 mrad off-axis. It operates at a fixed energy of 10.4 keV, monochromatized with a cryo-cooled Si (111) crystal at 16.5 m. A fixed-focus, 850 mm long toroidal mirror focuses the beam to 36.5 m. With a maximum sample-to-detector distance of 4 m, a beam size of ~1.5 × 0.4 mm² and a flux of ~5×10¹² ph/s are achieved, with a SAXS resolution of ~300 nm. Applications include high-throughput SAXS/GISAXS in structural biology, materials science, and slow dynamics. Commissioning is planned for early 2027.
The HB-SAXS beamline employs a 2 m in-vacuum undulator (109 poles, 5.2 mm gap), delivering 4.5–17 keV radiation within a 40 µrad × 40 µrad cone. A dual monochromator (Si (111) and multilayer) combined with Kirkpatrick–Baez mirror optics enables variable focusing between 32 and 38 m. The beam size is ~0.2 × 0.13 mm², with a flux of 10¹²–10¹⁴ ph/s and SAXS resolution better than 500 nm. This branch targets fast structural transitions; reflectivity and simultaneous X-ray spectroscopy are under evaluation.
The mirrors can be removed to provide highly coherent radiation for photon correlation spectroscopy. Future upgrades include secondary optics to achieve ~5 µm spot size for 3D tensor SAXS and scanning SWAXS. Commissioning of the first part is planned for late 2027.