Intense electron emission from graphite nanocraters and their application to time-resolved x-ray radiography

Abstract

A high-density electron emission more than $\text{20\hspace{0.17em}}{\mathrm{mA/cm}}^2$ was achieved from a cold cathode fabricated by simple plasma etching nanocraters onto a graphite substrate. The magnitude of the field enhancement factor was about 30 000, which is similar to that for the highest reported performance for carbon nanotube. The performance of this cathode was demonstrated by obtaining high-intensity pulse x-ray generation. High-speed x-ray radiography images of dynamical processes of the order of 10 μs were successfully shown, thus offering a new technique for nondestructive inspections.