Pressure amplification in single-stage gas launchers via Mach-stem formation

We present a pressure amplifier that integrates with single-stage gas launchers and enhances the accessible range of sample pressure states. The design of the amplifier was guided by hydrodynamic simulations. Using a convergent shock geometry, the amplifier generates pressures of up to 4.3 times greater than those achievable through direct impact. The evolution of the shock fronts through the amplifier was captured using ultrahigh speed x-ray phase-contrast imaging, and the velocity history of shocked samples was measured using photonic Doppler velocimetry to ascertain output pressures of the amplifier. Pressures of up to 40 GPa were observed in copper and iron samples as well as the observation of phase-transition kinetics in iron (α–ϵ transition). These results demonstrate the utility of the pressure amplifier in allowing a wider range of material phase space to be explored with single-stage guns.