New field-emission x-ray radiography system

A new field-emission x-ray radiography system based on our design is described. The key component of the system is a triode-type x-ray source with a built-in nanostructured electron source. The electron source is comprised of palladium-induced carbon nanofibers, which continue to field-emit electrons for more than 10 h at 2×10-7Torr with a fluctuation of ±8%. Feedback control of the potential of the electron-extracting electrode, or the gate, reduces the current fluctuation to ±0.5%, but this current regulation does little to improve the image resolution. Our system provides sharp x-ray images of both biological and nonbiological samples