Evaluating the Impact of Multiply-charged Ion Radiation on Nb-based Superconducting Devices

Multiply-charged ions (MCIs), commonly found as components of solar winds, are a major contributor to space electronics failures due to their large potential and kinetic energies. Studying how MCI irradiation impacts superconducting materials such as Niobium (Nb) is particularly interesting for developing high-fidelity particle and radiation detectors. When MCIs interact with a surface, their stored energy can be released in the form of x-rays, secondary electrons, and ions. Here, we present measurements of x-rays and secondary electrons emitted from Nb samples irradiated with low and medium energy Ar⁸⁺ MCIs. Real-time changes in the surface composition of the Nb samples are tracked using a combination of Auger electron spectroscopy and X-ray emission analysis. These measurements are important for the development of reliable surface preparation techniques for Nb and also provide insight into how the surface properties change under charged particle irradiation. The real-time secondary electron and x-ray measurements are related to the basic charge and energy exchange physics between the MCIs and the Nb surface. Additionally, erosion effects caused by MCI exposures were analyzed through atomic force microscopy and electrical characterization.