Investigating the effects of high-energy pulsed protons on the surface and structural properties of copper and tungsten by MTPF-2 plasma focus device

In the present work, the results of using a low energy plasma focus device MTPF-2, in order to investigate the destructive effects of shockwave and high-energy ions on tungsten and copper surfaces, are presented. Tungsten and copper were selected as a relatively hard and soft metals, respectively. The samples were placed at a distance of 8 cm from the upper anode surface at zero degrees relative to the symmetry axis and were exposed to ions and a shockwave from 20 electrical discharges. The discharge voltages were 12 kV and carried out in hydrogen gas at a pressure of 1mbar. By using the optical microscopy images, scanning electron microscopy images, x-ray diffraction spectroscopy, and x-ray diffraction analysis, the reference and irradiated samples were analyzed. The results, in addition to confirming the performance of the MTPF-2 device to be used in such studies, showed that the collision of ions and the shockwave creates, cracks and blister at the surface of the tungsten, lead to the creation of cracks, blisters, and melting of the copper surface, and changing the crystalline parameters such as the Bragg angles, the intensity of the peaks of the diffraction spectrum, and the distance between the crystalline plates. The calculations, which were performed by using the Scherrer’s formula also show a change in the average grain size of both metal surfaces.