Diffraction of Acoustic Compression–Tension Pulses Generated by High-Density Nanosecond Electron Beam in Solids

Propagation of longitudinal acoustic signals through a D16T aluminum alloy, polycrystalline copper, and single-crystalline silicon was studied experimentally by laser interferometry. An asymptotic differentiation phenomenon was revealed in the acoustic signal in the transition from the near to the far wave field. Our experimental data analysis and theoretical calculation are indicative of the diffraction character of the phenomenon.