Field electron emission from composite cathodes with a nanostructured surface

Field electron emission from composite copper–carbon (Cu–C) cathodes with a nanostructured surface is studied experimentally. The emitting surface of the cathodes is formed by a high-voltage vacuum discharge. The morphology and the elemental composition of the emitting surface are analyzed. The current–voltage characteristics are studied at working voltages of 1.8–5.6 kV in anode–cathode gaps of 0.5 mm. It is found that in technical vacuum conditions, the emission current from the Cu–C cathode at such voltages is 5–270 $\mu$A.