Single crystalline molybdenum nanostructure for generating reflective micro-focal spot X-rays: Structure-controllable preparation and characteristic-selectable radiation

Abstract

The use of properly designed nanostructured anode targets enables direct generation of high performance X-rays. In particular, this scheme has attracted widespread research interest for obtaining micro-focal spot X-ray radiation. In this study, we developed a thermal evaporating deposition technique and achieved controllable preparation of different single crystalline molybdenum (Mo) nanostructures by exploiting the lattice matching relationship between the substrate and the product crystal orientation. When used as an anode target for a reflective X-ray radiation device, these nanostructured Mo single crystals exhibit advantages over traditional targets at larger radiation angles. Further experimental and simulation results demonstrate the geometric characteristics of these Mo nanostructures and their correlation with the radiation intensity, focal spot size, and brightness of the generated X-rays. Among them, a unique frustum of square pyramid single crystalline Mo nanostructure stands out, due to its combination of three-dimensional body feature of nanostructures and radiation plane feature of planar targets. The research results not only provide a class of nanostructured anode target materials for reflective X-ray sources with different radiation angle requirements, but also make it possible to design and develop miniaturized devices for X-ray sources with selectable radiation performance and micro-focal spot.