High-rate pressurization by drop-weight impact

High-pressure pulse is generated in the gasket region when a tungsten carbide opposed anvil setup backed by a rigid support is impacted by a low-velocity projectile. The pressure increases linearly with time, except near the start and the peak of the pressure pulse. The pressurization-rate in the region of linearity can be varied over a range 0.01 to 0.1 GPa(as)-1 by varying the momentum of the projectile. The amplitude of the pressure-pulse increases with increasing pressurization-rate,and is -6.5 GPa at a pressurisation-rate 0.1GPa(as)-1. The pressure induced transitions in the bi and Yb have been examined under rapidly increasing pressures. It is found that Bi(I)-bi(II) transition is complete in -8as at a pressurization-rate 0.1 GPa(as_-1. The fcc- bcc transition in Yb can be considerably over-driven by rapid pressurisatio