Radiation Defects Induced by Proton Exposure in Hollow Zinc-Oxide Particles

Zinc-oxide powders consisting of spherical hollow particles are obtained by hydrothermal synthesis. Comparative analysis of the diffuse reflectance spectra and their changes after irradiation with 100-keV protons of powders of micrometer-sized hollow and bulk particles of zinc oxide is carried out. We present the results of the physical and mathematical simulation of the interaction of a low-energy proton beam with zinc-oxide particles, using the GEANT4 software package. The calculation results and the experimental data are compared. Hollow particles have a greater radiation resistance to protons compared to micrometer-sized bulk particles. The effect is determined by the absence of radiation-induced defects in the volume of spherical particles, a large ionization loss associated with surface-defect formation, and the significant relaxation of radiation-induced defects in a thin layer of spheres.