Potential Effects in the Interaction of Highly Charged Ions with Solid Surfaces

Abstract

In the field of nuclear fusion technology, Er₂O₃ thin film is a candidate for the coating material of the blanket of thermonuclear fusion reactor. It is known that the luminescence of Er₂O₃ provides information on its crystallinity. We observed luminescence of various samples including Er₂O₃ during the irradiation with highly charged ions produced by an electron beam ion source (EBIS) as a function of charge state and kinetic energy of incident Ar ions. We found that the luminescence intensity non-linearly rises as the charge state increases and is independent of kinetic energy. This demonstrates that the luminescence arises from the potential energy of highly charged ions rather than the kinetic energy. Emission spectra from various samples indicate that emission from sputtered atoms, mostly atomic hydrogen, is remarkable, while emission lines from the surface layers due to transitions among Stark splitting were observed for Er₂O₃ samples. [DOI: 10.1380/ejssnt.2016.1]