Shock compression of aluminum, copper, and tantalum

Hugoniot curves for Al (alloy 11000), Cu (type oxygen-free high-conductivity), and Ta have been measured in the shock pressure range 30–430 GPa (0.3–4.3 Mbar) with a two-stage light-gas gun. Impactor velocities were measured to 0.1% by flash radiography. Shock velocities were measured to 0.5–1.2% with an electronic detection system with subnanosecond time resolution. Our data and those of other workers were fitted to a linear relation between shock and mass velocities. The fractional standard deviations of the data from the fits range from 0.6 to 0.9% for the three metals. Methods of data analysis and error analysis for individual data points and for the least-squares fitting to the data sets are presented. Bands of uncertainty about the fits, arising from experimental uncertainties in the data, are presented and are used to calculate the systematic error introduced by the method of shock-impedance matching. The accuracy of the data and of the fits qualifies these metals as equation-of-state standards for shock-wave experiments.