The instrument is dedicated to the determination of physical characteristics of materials under high pressure and temperature conditions, using a 2000 ton force large-volume device.

Status: open

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We operate in 3 modes: 1- or 2- compression stages and 1-stage (6/6) for deformation studies. Diffraction data are collected in monochromatic mode at energies of typically 33 or 55 keV (1013s−1 flux), generated from the emission of a U18 undulator, and selected by a Cinel Si(111) monochromator with beam-position feedback. Beam sizes are typically 1 mm^2 when not limited by anvil gaps. Currently, we operate using a 2-D PILATUS3 X CdTe 900K-W-ESRF detector. Full two-dimensional data can be taken at a sub-second time and down to 0.6 Å real-space resolutions. 2-stage switchable focusing (Be, Al) is also available to provide beam sizes down to 20 μm (on the detector or sample).

In 1-stage mode, we can operate with horizontal or vertical furnaces, cubes mounted in 10 mm EL boron epoxy and compress samples to 10 GPa. Temperatures obtained with a graphite furnace (2.9 mm OD, typical) can exceed 1800 K. This assembly is modified, by introducing hard alumina pistons, for deformation studies. These use the independent 'Up' and 'Down' primaries of the press tooling to change the shape of the sample under load. This can be both contracting and extending and cycled through null stress states. Deformation studies too are conducted to above 10 GPa, at high temperature, with strain rates of 10-5-10-6 sec-1 (typical) to a maximum total accumulated strain of 30-35%.

Two-stage experiments are currently offering Users the possibility to exceed 30 GPa (by operating with a set of hardened primaries) and 2000 K, using a variety of sample geometries - 25 mm to 7 mm octahedra are used. Given the natural geometry of our cubic device, regular sample geometry is complex, however, we can run horizontal or vertical furnace geometries should the need require. To 10 GPa, graphite furnaces are most popular and, at higher loads, other metal or semiconductor furnaces can be used. These are cut in-house with special windows to avoid absorption.

Sample alignment is by x-ray camera on its 9 independent axes (4 x vertical [electronically coupled, mechanically independent]; sample-centring X-Y pair, rotation and further rotation-centring X-Y pair). The press is then mounted on an omega stage, allowing the collection of single-crystal datasets or augmenting the 2Theta range possible by working in an asymmetric setting (to 26 deg 2TH h plane, 55 deg v plane). The detector mounts are fully independent of any press movement. All parameters of the experiments are recorded, and thermocouple values (C/D, typical) are read directly by control software. The furnace is controlled by software PID, which drives the fast-programming 6 kW supplies (high V or high I).

The Drickamer, to above 35 GPa, and two-stage 6/8 operations can be coupled to TOhm resistivity configurations. Ultrasonic experiments are possible at pressures above 30 GPa with a 10 s acquisition rate.

Sample environments for hydrogeneration reactions are possible.