大型放射光施設 SPring-8

Language：English

Speaker：Dr. Frederico Alabarse

Affiliation：Elettra Sincrotrone Trieste

Title：Xpress beamline: Diffraction at Extreme Conditions – Elettra Sincrotrone Trieste

Abstract：
The Indo-Italian high pressure (HP) diffraction beamline, Xpress, at Elettra Sincrotrone Trieste, is constantly increasing its’ operational performances by adding and improving new instruments. Today, the beamline utilizes the synchrotron radiation from a superconducting wiggler to produce a 25 keV monochromatic X-ray beam focused on a large area detector for data acquisition in angle dispersive mode, allowing powder and single crystal (SC) diffraction experiments to be performed under HP conditions by using diamond anvil cells (DAC), comprising an online fluorescence spectrometer (ruby, Sm²⁺:SrB₄O₇). The beamline station is equipped with state of the art facilities for HP manipulation (microdriller, automatic pneumatic pressure controller, etc). The partner institute, IISc Bengaluru, recently added three new dedicated HP setups compatible to DAC: (i) a low temperature (T) closed cycle He-cryostat (85deg 4θ X-ray opening), reaching down to 10 K (Almax easyLab/ JANIS); (ii) still under improvement: a high T vacuum chamber, making use of internal and external heater, to reach up to 1000 K (LOTO-eng); and (iii) an offline micro Raman spectrometer (Renishaw, class 4). On the top of this, the beamline team, in collaboration with the Elettra’s Research Engineers group, had in house developed: 1) a cryogenic loader to permit the loading of a variety of gas media, such as Ar, N₂, O₂, CH₄, etc.; and 2) a second vacuum chamber to be used for HP-high T experiments (also 85deg 4θ X-ray opening) by using an external ring heater (tested up 700 K). For the measurements at room T, recently a Chi motor was added to be combined with the rotation at the Phi during the measurements. Still on new loading possibilities, a commercial gas loading system (Sanchez) permits DAC to be loaded with gases such as He, Ne, etc. Beamline data collection and control graphical user interface is being continuously improved by the Elettra’s Information Technology group to handle well all these new developments even on remote mode. Elettra is currently undertaking an upgrade program, Elettra 2.0 (shutdown from mid-2025 to end of 2026), to reach an even brighter and coherent synchrotron radiation source. Under this project, Xpress beamline recently received a new large area detector, PILATUS3 S 6M (from DECTRIS), which key advantages are: direct detection of X-rays; single-photon counting; excellent signal-to-noise ratio and very high dynamic range; short readout time and high frame rates; shutterless operation; modular detectors enabling multi-module detectors with large active area. Still under the Elettra 2.0 upgrade program, Xpress very recently obtained a space dedicated to loading and HP manipulation: Elettra’s High Pressure Lab. Xpress developments are in progress, perspectives for a near future are powder and SC diffraction under HP (up to megabar pressures) together with variable temperatures from few to several hundred Kelvins. Proposal submission deadline (open again from end of 2026) are typically on mid-March and -September. Elettra-users may benefit from partial or total reimbursement of travel and living expenses during their stay, thanks to specific programs or agreements between institutions, such as: a) International users support – up to 2 scientists (worldwide); b) ICTP-Elettra users program – up to 3 scientists of developing countries (total reimbursement); and c) Indo-Italian POC project – up to 3 scientists from Indian institutions. The talk will present all the above mentioned beamline characteristics together with some recent scientific highlights performed under extreme conditions of pressure and temperature.

*Corresponding author: frederico.alabarseelettra.eu
Keywords: high pressure physics, extreme conditions, synchrotron radiation