The so-called "Sumitomo Press" is a 2000-ton uniaxial split-sphere apparatus (USSA-2000) which is capable of generating
pressures to 30 GPa and temperatures of 3000 K for sample volumes of 3 mm3
, or pressures of 10 GPa for sample volumes of 30
. It is particularly well-suited for synthesis experiments which require the generations of simultaneous high pressures and
temperatures in large sample volumes for sustained periods of time. The recovered samples are later studied by a variety of analytical
techniques, including X-ray diffraction, electron microprobe and microscopy, Brillouin and Raman spectroscopy, various synchrotron
techniques, and ultrasonic interferometry in other Mineral Physics Institute-affiliated laboratories.
The pressure assembly used in the Sumitomo Press consists of eight individual Tungsten Carbide cubes with truncated corners. The size of the cubes and their truncations vary depending on the desired pressure and sample volume of the experiment (generally designated as 8/3 and 14/8), though the basic assembly is the same regardless of size, and is shown at right in the form of a wooden block model (for a larger picture, click the image). The truncated corners of the eight cubes for an octahedral space at the center, which is where the cell assembly containing the sample material is placed. Pressure is applied vertically by the press, and as pressure is increased, the cubes are squeezed together, applying directionally-uniform pressure to the sample inside.
The octahedral pressure medium used in this split-sphere apparatus is made of either MgO or MgO + spinel and has the center drilled out to accomodate the cell assembly. A diagram of the cell assembly and all of its parts can be found at the left (for a larger diagram, simply click on the image). This diagram is specifically of the 14/8 cell assembly, though the 8/3 assembly is similar in nature, and was provided by Kurt Leinenweber at Arizona State University. The gray area at the center that is labeled "sample configuration" varies depending on the experimental sample material and the type of capsule used to house the sample.
For more information on the cell assemblies used in these experiments conducted in the Sumitomo Press, see the Cell Assemblies