Equation-of-state, sound speed, and reshock of shock-compressed fluid carbon dioxide

Abstract

Mechanical equation-of-state data of initially liquid and solid CO2 shock-compressed to terapascal conditions are reported. Diamond-sapphire anvil cells were used to vary the initial density and state of CO2 samples that were then further compressed with laser-driven shock waves, resulting in a data set from which precise derivative quantities, including Grüneisen parameter and sound speed, are determined. Reshock states are measured to 800 GPa and map the same pressure-density conditions as the single shock using different thermodynamic paths. The compressibility data reported here do not support current density-functional-theory calculations, but are better represented by tabular equation-of-state models.

A Comprehensive Review of High-Pressure Laser-Induced Materials Processing, Part II: Laser-Driven Dynamic Compression within Diamond Anvil Cells

“…LDC-DAC systems include a pulsed laser system ((i), not shown), a focused laser beam (ii), a material sample to be compressed (iii), at least one diamond anvil (iv), a chamber gasket (v), and an optional laser target (xvii) placed at the laser focus. Diamond is commonly used for the transparent anvils (iv) in LDC-DAC experiments due to its high shock impedance, wide transmission bandwidth, and dielectric constant [22], although other materials, such as sapphire (Al 2 O 3 ) and quartz (SiO 2 ), have been utilised [32,[46][47][48]. In some experimental setups, the sample itself is the laser target, as displayed in Figure 2A [22,30,49].…”

“…In most configurations, however, a target comes before the sample to be compressed (See Figure 2B-D). The laser target's purpose is to absorb the laser light before it arrives at the sample; this target can be placed in several locations, such as at the inside surface of the incident anvil (Figure 2B) [24,25,[50][51][52][53], or on the exterior surface of the same anvil (Figure 2C) [54][55][56]-or on both surfaces of the incident anvil (Figure 2D) [29,46,47,[57][58][59][60][61]. Note that in the references for Figure 2C, the examples provided are not strictly L-DACs but are arranged similarly to that of an L-DAC (with a fully enclosed pressurised cell).…”

“…Note that in the references for Figure 2C, the examples provided are not strictly L-DACs but are arranged similarly to that of an L-DAC (with a fully enclosed pressurised cell). Many variations on these configurations have been attempted in the past [46,[62][63][64].…”

“…LDC-DAC experimentation has enabled condensed matter physicists to determine material densities, melting curves, Hugoniot curves, equations of state (EOS), and transport properties for many common elements and compounds over a wide variety of conditions [19,20,[24][25][26][27]. Furthermore, LDC-DAC methods have enabled geophysicists and planetary physicists to determine the properties of dense matter at conditions akin to those deep within planetary interiors, providing insight into the structure and dynamics present within the terrestrial planets [19,28].…”

“…Furthermore, LDC-DAC methods have enabled geophysicists and planetary physicists to determine the properties of dense matter at conditions akin to those deep within planetary interiors, providing insight into the structure and dynamics present within the terrestrial planets [19,28]. The technique has allowed researchers to better understand how lasers interact with matter-and how shock-/pressure-waves travel through materials at high pressures [27,29]. Although multi-stage DACs can achieve pressures greater than 380 GPa, when sample sizes greater than 20 µm across are to be compressed, the LDC-DAC mode is presently the primary means to achieve pressures >> 380 GPa [19,[30][31][32].…”