T. R. Diedrich

Cell assemblies for reproducible multi-anvil experiments (the COMPRES assemblies)

Abstract The multi-anvil high-pressure technique is an important tool in high-pressure mineralogy and petrology, as well as in chemical synthesis, allowing the treatment of large (millimeter-size) samples of minerals, rocks, and other materials at pressures of a few GPa to over 25 GPa and simultaneous uniform temperatures up to 2500 °C and higher. A series of cell assemblies specially designed and implemented for interlaboratory use are described here. In terms of the size of the pressure medium and the anvil truncation size, the five sizes of assemblies developed here are an 8/3, 10/5, 14/8, 18/12, and 25/15 assembly. As of this writing, these assemblies are in widespread use at many laboratories. The details of design, construction, and materials developed or used for the assemblies are presented here.

High-pressure cells for in situ multi-anvil experiments

A new series of high-pressure cells for in situ multi-anvil experiments is described. The cells are based on the conventional COMPRES cells, but modifications are made to improve the passage of X-rays. The modifications include cutting slits in parts of the assemblies that have very high X-ray absorption, such as lanthanum chromite and rhenium, the use of low-Z thermal insulation, such as forsterite, in place of zirconia, and the partial replacement of zirconia by MgO equatorial windows combined with a mullite octahedron. Details of the designs, thermal characterizations, and examples of the application of these cells are described.