Study of using pulsed beams to increase the radiation resistance of nitride ceramics to helium swelling

The work is devoted to the study of the use of pulsed beams with a high current density to create a highly defective layer in nitride ceramics to increase the radiation resistance to helium swelling. Scanning electron microscopy, X-ray diffraction, and atomic force microscopy were used as research methods. It was established that irradiation with a pulsed beam leads to a change in the morphology of the surface layer, not exceeding 0.5–0.7 μm thickness with the formation of a large number of grain boundaries and defects resulting from the impact of a high-density ion pulse over a nanosecond time interval. Using the X-ray diffraction method, it was found that irradiation with a pulsed beam leads to a slight change in stresses and dislocations in the structure, which creates additional obstacles to helium swelling. During tests of the radiation resistance of nitride ceramics to helium swelling, it was found that for modified samples a decrease in helium swelling and He²⁺ concentration in the structure of the surface layer was observed, while for unmodified samples, helium bubbles were formed, whose size was from 70 to 200 nm. The presence of these helium inclusions is due to the low solubility of He²⁺ in the structure, as well as the high mobility of He²⁺ and the ability to agglomerate with the formation of gas cavities in the structure.