High Spatial Resolution Cone Beam X-ray Imaging System Based on a Scanning Electron Microscope

摘要: A high-spatial-resolution cone-beam X-ray imaging system has been realized based on the micro spot X-ray source generated by a high-quality electron beam from a Scanning Electron Microscope (SEM). The diameter of the X-ray source was estimated to be 1.0 μm based on Geant4 simulation when the primary electron beam size is 10 nm, which is mainly determined by the electron injection range inside the copper target, and the X-ray source was found to follow double Gaussian distribution. The clear X-ray images of a 400-mesh copper mesh have been acquired, and the best spatial resolution of the system was tested to be 7.1 μm under magnification factor of 68.8. The X-ray imaging on distinct head regions of a Carebara diversa ant have been realized, the organs like the ant’s jaw and eyes were clearly shown, and the imaging range can be adjusted easily. These results demonstrate that this imaging system has high magnifications and precise spatial resolution, and is able to achieve clear and practical X-ray imaging for very small biological specimens.