COMPRES Multi-Anvil Cell Assembly Project K. Leinenweber, J. Tyburczy, T. Sharp Arizona State University Report

Multi-anvil runs that work are worth a great deal, while ones that do not work are very costly. If an experiment can work once, its success should be repeatable. But this requires good designs, and a high degree of reproducibility in the materials and techniques. An effort to standardize multi-anvil techniques is worthwhile, but should be a shared community effort. Thoughts that started this project:

In this project, we are working on the design and methods of high-pressure multi-anvil experiments, and on bringing together all of the components for these experiments in a community effort.

A. A list of the laboratories using COMPRES cells: Argonne National Laboratories Arizona State University Delaware State University Geophysical Laboratory Lawrence Livermore National Laboratories NASA Johnson Space Center Stony Brook University University of Arizona University of California at Davis University of California at Riverside University of New Mexico B. A list of additional laboratories testing COMPRES materials: American Museum of Natural History Brookhaven National Laboratories California Institute of Technology Georgia State University University of Hawaii University of Minnesota C. Foreign affiliates: Daresbury Laboratory University College London University of Western Ontario

Assembly namePeak pressureProven temperatureDesign 8/325 GPa2319 °CRhenium furnace 10/520 GPa2000 °CRhenium furnace 14/8 “G2”13 GPa1200 °CGraphite box furnace 14/8 “Bay-Tech”15 GPa1400 °CGraphite/LaCrO 3 step furnace 8/3 in-situ25 GPa2000 °CSlitted rhenium furnace 10/5 in-situ20 GPa2000 °CSlitted rhenium furnace 14/8 “G2” in-situ13 GPa1200 °CGraphite box furnace, forsterite sleeve 14/8 “Bay-Tech” in-situ 15 GPa1500 °CGraphite step furnace, MgO equatorial window, mullite octahedron Summary of the current standard COMPRES multi- anvil assemblies

This is possible because of the COMPRES lathe, shown here with all the tools set up for the previously shown LaCrO 3 sleeve with x-ray windows.

Dirty picture of the lathe.

Animation showing the machining sequence, and the generated computer code for it.

Those inner parts are combined with octahedra injection- molded with the thermocouple grooves already in them, for reproducible alignment.

Metal furnaces, gaskets, and paper are now all laser-cut.

LaCrO 3, many zirconia, graphite and BN parts are machined. MgO, some zirconia parts are extruded.

Pressures are calibrated as part of the project, and the effect of T on P is also calibrated; this information is provided with the assemblies.

We are trying a more formal system of ordering and supply. 30 “orders” have been made for established materials, 25 filled. Novel materials are provided for free as part of the research program like before (example: the new mullite spheres for the D-DIA, Durham et al COMPRES abstract and poster). COMPRES is acknowledged in published work that uses the materials. Once standardized, and when possible, the work is migrated to outside companies. The latest on how we are proceeding:

Ken Domanik (U of A) suggested a higher- temperature design for the 14/8, we tried it and it is now in use. Mullite spheres idea of Bill Durham (MIT) was realized by this project, tested in the D-DIA at NSLS (See Bill’s poster). In-situ x-ray assemblies have been optimized by back-and-forth with Yanbin Wang at GSECARS beam line sector 13 at APS. Other in-situ development is ongoing with a NASA group (Righter, Danielson, Campbell). Recent examples of feedback between the community and the project ( ):

Upcoming projects: Protect the lathe for further prolonged use with ceramics by improving the air handling system (this week!). Reduce some of the bottlenecks: improve our raw ceramic supply, automate the feed of the ceramics into the lathe to save time. “Normalize” the supply and timing to respond to the fact that some labs seem to be depending on this project for their research.

Instrument Maker/Designer Sr. Bill Chapin is working on the newest dust removal system this week.