A new 6-axis apparatus to squeeze the Kawai-cell of sintered diamond cubes

Eiji Ito, Tomoo Katsura, Daisuke Yamazaki, Akira Yoneda, Masashi Tado, Takahiro Ochi, Eiichi Nishibara, Akihiro Nakamura

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


In order to overcome disadvantages of the DIA type press in squeezing the Kawai-cell, such as uneven compression between the upper and lower anvils and the four surrounding anvils and frictional loss of applied load in the guide block, we have developed a new 6-axis apparatus in which the movements of the six anvils are controlled by a servo mechanism. It is possible to keep the Kawai-cell cubic within an accuracy of ±2 μm during compression and decompression. Pressure generation using sintered diamond cubic anvils with edge length of 14.0 mm and a truncation of 1.5 mm has been carried out up to ca. 60 GPa by measuring electrical resistance of GaP, Zr, and Fe2O3. The results are compared with our previous calibration, carried out using an almost the same sample setup for identical anvils at SPring-8, by means of in situ X-ray observation. It is demonstrated that a significant amount of the applied load is lost by friction when the Kawai-cell is squeezed in the DIA type press. The load loss increases with increasing load, or pressure, and amounts to 45% at ca. 60 GPa. Therefore the 6-axis apparatus is very advantageous to generate higher pressures in the Kawai-cell. However, individual control of the anvils sometimes induces a runaway advancement of the anvils which brings about an abrupt increase of pressure.

Original languageEnglish
Pages (from-to)264-269
Number of pages6
JournalPhysics of the Earth and Planetary Interiors
Issue number1-4
Publication statusPublished - May 2009


  • A 6-axis apparatus
  • A servo mechanism
  • Pressure generation
  • Sintered diamond
  • The Kawai-cell

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Geophysics
  • Physics and Astronomy (miscellaneous)
  • Space and Planetary Science


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