HR: 14:40h
AN: MR13A-05    [Abstracts]
TI: Synchrotron Radiation High Pressure Systems for Mineral Physics at Spring-8
AU: * Shimomura, O
EM: simomura@spring8.or.jp
AF: Spring-8 / JASRI, Kouto 1-1-1, Mikazuki, Hyo 679-5198 Japan
AB: Synchrotron radiation (SR) has been recognized as an indispensable tool for the in-situ structural study at high pressure for mineral physics, and high pressure SR experiments are conducting at various SR facilities over the world. At SPring-8, there are two kinds of high pressure and high temperature systems with SR for mineral physics. One is a multi-anvil system, and the other is a laser heated DAC system. Kawai-type double stage press with a thrust of 1500 ton, named SPEED1500, was one of the first apparatuses installed at SPring-8 in 1997. In situ observation of olivine-spinel transition boundary became a sensational problem for the determination of transition zone boundary. In addition to the diffraction experiments, viscosity measurement technique has successfully been developed. A trial of topography experiment to reveal the transition mechanism was conducted, and the simultaneous measurement of diffraction and ultrasonic velocity is now underway. In order to perform the experiment at higher pressures, a new double-stage system named SPEED MkII was installed in tandem with SPEED1500. SPEED MKII can generate pressures higher than 50 GPa with sintered diamond anvils. Press oscillation mechanism can give better quality of powder diffraction data. A typical example is the precise determination of the B1-B2 transition of NaCl. The laser heated DAC system consists of a YLF laser and X-ray lens to focus both laser and X-ray in a few tens of a micrometer region, and can achieve 200 GPa and 2500K. Recent observation of the post-spinel transition is an excellent topic. Further interesting results obtained with these high pressure systems will be presented in more detail.
DE: 8124 Earth's interior--composition and state (old 8105)
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting