Labquakes from high-pressure synchrotron experiments

Labquakes from high-pressure synchrotron experiments

by Thomas P. Ferrand, Earthquake Research Institute, Tokyo, Japan

The D-DIA is a large-volume triaxial press able to confine material up to tens of gigapascals. Here, the six anvils of the D-DIA squeeze a cube of boron-epoxy, in which the deformation assembly is located. The 6-mm truncation allows to easily reach pressures between 1 and 4 GPa in millimetric samples. On the picture, four of the six anvils are visible and the cube shows its shape after deformation.
Most of the anvils are made of tungsten carbide, but for X-ray diffraction experiments two of the four horizontal anvils consist of sintered diamond, which is almost transparent to X-rays. On the left side of the picture you can see that the diamond anvil holder is truncated in order not to hide the X-ray diffraction pattern.
The plus of our experiments actually is very subtle on the picture. On top of the right anvil, you can see a white wire. Actually, each anvil holds a piezoelectric transducer, connected to the computer via such wires. Indeed, in this set of high-pressure deformation experiments, we use synchrotron technology and acoustic emissions monitoring in the same time to understand how earthquakes are triggered.