Kurt Leinenweber Arizona State University

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COMPRES Multi-anvil cell assembly development

• Kurt Leinenweber, James Tyburczy (Arizona State
  University)

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Some collaborators

• Caltech (Jed Mosenfelder) 14/8, 8/3 (requested)
• Case Western (Jim Van Orman) 8/3
• Canberra (Tom Sharp) 8/3
• American Museum of Natural History (Rondi Davies)
  8/3
• Urbana Champaign (Jie Li) 8/3
• Carnegie (Yingwei Fei, Shantanu Keshav and
  Alexandre Corgne) 8/3
• Stony Brook (Jiuhua Chen) 6 mm mullite cubes on
  order 8/3 request 8 mm mullite cut

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Some more collaborators

• Daresbury (David Price, Ray Jones, Ed Bailey).
  In-situ calibration of hybrid assemblies
• Argonne (Yanbin Wang) In-situ calibration of
  opaque assemblies.
• (At ASU development of 8/3, 10/5, 14/8
  assemblies)

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Design considerations

• Try to achieve
• High precision.
• High success rates.
• Low cost, ready availability.
• Consistency between laboratories.
• Consistency over time.
• The best developments are those that have many or
  all of these characteristics at once.

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Steps to increase precision

• Think about all the variables that could affect
  the pressure.
• Eliminate them if possible.

Gasket placement could affect the pressure.
Problem avoided by using pre-cut paper.
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Precision (cont.)

• Octahedron injection-molded.
• Rhenium furnace cut by EDM.
• LaCrO3 sleeve turned and slotted by lathe.
• Alumina inner pieces made on a dicing saw.

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Steps to increase success rates

• Obtain a more exact description of popular
  lore.
• Keep track of success rates for different
  configurations - change them if the success rate
  could be higher.
• Also good fit of octahedron and gaskets use of
  nesting plates.

Pre-slotted octahedron (new)
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New pressure media
Injection-molded octahedra (MgO/spinel). Also
mullite cubes are being made for the DIA.
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Automated lathe
Lathe (note the hood attachment!)
Slotting a lanthanum chromite sleeve
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Gaskets!

• The current rate-limiting step for this project!
• We are improving our automated milling, and
  testing laser-cutting. The best technique will
  depend on the size (smaller gaskets laser.
  Larger gaskets milling).

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Consistency between laboratories
Strain cube
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Consistency over time

• Document the sources of materials, and their
  properties (composition, density, dimensions,
  etc.). Beware of products that may be
  discontinued!

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Upcoming developments

• Develop 10/5, 18/11, and 25/15 COMPRES
  assemblies.
• New 14/8 zero thermal gradient, x-ray
  transparent assembly with smaller pressure loss
  at very high T.
• New ceramics In hand forsterite insulation,
  spinel insulation, TiB2/BN machinable composite
  furnace, mullite pressure medium. In development
  or proposed TiO2 insulation, SiC furnace.
• (Also could use a better pressure standard for
  temperatures above 1200 - 1400 C).

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Upcoming plans

• Hands-on training course at Argonne (joint
  between this project and Y. Wang). (not during
  Sept shutdown or Dec/Jan holidays at Argonne).
• Cell design summit meeting in Arizona?
• Continued collaborations, developments, and data
  gathering with the COMPRES assemblies.