Radiation effects on cathodoluminescence of albite

Abstract

He+ ion implantation on albite (Minas Gerais, Brazil) at 4.0 MeV, corresponding to the energy of α particle from 238U fission, has been conducted to clarify the radiation effects of α particles from radioactive minerals on cathodoluminescence (CL) of albite. CL of albite results in various emission bands at ~380, ~560, and ~740 nm, and in the UV range. Red emission at 700-750 nm is detected in the CL spectra of the implanted samples. Total CL intensities of these UV, blue, yellow, red, and IR emissions vary among the samples. High-resolution CL imaging of the cross-section samples shows a CL halo on the implanted surface of approximately 14 μm thickness, which is consistent with a theoretical range of α particles of 4.0 MeV. It was first confirmed experimentally that the CL halo is created by α particles. The deconvolution of CL spectra in the red emission range by Gaussian fitting provides the component at 1.861 eV that is attributed to a radiation-induced defect center produced by He+ ion implantation. The intensity of the component at 1.861 eV linearly correlates with the dose density of He+ implantation on albite as a function of the population of the radiation-induced defect center, regardless of other factors such as concentration and distribution of other emission centers, existence of microstructures and textures, and crystallographic orientation. The CL spectral deconvolution has a high potential for quantitative evaluation of the radiation dose of α particles from natural radionuclides on albite for a geodosimetry.