COMPRES Multi-Anvil Cell Assembly Project

K. Leinenweber, J. Tyburczy, T. Sharp

Arizona State University

2006-2007 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 name Peak pressure Proven temperature Design

8/3 25 GPa 2319 °C Rhenium furnace

10/5 20 GPa 2000 °C Rhenium furnace

14/8 “G2” 13 GPa 1200 °C Graphite box furnace

14/8 “Bay-Tech” 15 GPa 1400 °C Graphite/LaCrO3

step furnace

8/3 in-situ 25 GPa 2000 °C Slitted rhenium furnace

10/5 in-situ 20 GPa 2000 °C Slitted rhenium furnace

14/8 “G2” in-situ 13 GPa 1200 °C Graphite box furnace, forsterite sleeve

14/8 “Bay-Tech” in-situ

15 GPa 1500 °C Graphite 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 LaCrO3 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.

LaCrO3, 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.

Pressures at 1200 °C

0

5

10

15

20

25

0 200 400 600 800

Force (Tonnes)

Pre

ssu

re (

GP

a)

8/3

10/5

14/8

25/15

Effect of temperature on pressure of 10/5 assembly (CsCl pressure standard)

10

12

14

16

18

20

22

0 200 400 600 800 1000 1200 1400 1600

Temperature (oC)

Pre

ssu

re (

GP

a)

454 tonnes

363 tonnes

635 tonnes

• 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. 2007 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 (2006-2007):

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.