Mechanical and optical properties of vanadium under shock picosecond loads

The evolution of compression pulses generated by a femtosecond laser in micron-thick vanadium film samples has been studied by the interferometric method with continuous recording of motion in the picosecond range. The relation of the velocity of a shock wave and the particle velocity behind its front indicates the elastic character of shock compression at pressures up to $46$ GPa, for which the shear stress is $15.8$ GPa. The measured spall strength reaches $21.8$ GPa at a strain rate of ${\sim}\,10^9\,$s$^{-1}$. The picosecond dynamics of the reflection coefficient of vanadium, which indicates the excitation of its electronic subsystem under “cold” compression by an ultrashort shock wave, has been detected.