Fig. 2.

Stress and strain measured in run 1. a Pressure at the center of the toroidal-DAC (t-DAC) measured using the XRD signal of rhenium gasket and rhenium equation of state³³ vs. membrane pressure. The membrane pressure is proportional to the load applied on the diamond table. The compression stages (I, II, and III) are discussed in the text. b Distribution of pressure measured every 3 μm along a 13 × 13 points grid, with the same method. The pressure at the center of the t-DAC is 585 GPa. The dashed line indicates the limits of the central flat and the yellow disc the extension of gold sample. c Thickness of the rhenium gasket measured using monochromatic X-ray (λ = 0.3738 Å) absorption profiles. The profiles have been measured at various pressures indicated by dots with the same color in the sample P vs. membrane P curve in a. The red profile corresponds to the data collected just before anvils breakdown. d Enlarged view of two profiles: the strain (“cupping”) of the central flat can be clearly seen