摘要
It is well known that ultrasonic pulses can be generated in condensed materials by thermal sources caused by intense particles beams bombardment, such as the beams of photons, electrons, protons, and ions. For energy ion beam impinging on a material, the beam deposits its energy gradually along the ion trajectory and a cylinder of heated material is created. The pressure in the heated zone initializes a two-dimensional shock wave or ultrasonic wave (along the radial direction as well along the beam direction). We refer this effect
