The pseudospark cathode has the remarkable property of macroscopically homogeneous electron emission at very high current density (>1 kA/${\mathrm{cm}}^2$) over a large area (some ${\mathrm{cm}}^2$). Experimental results and the model presented here provide evidence that the pseudospark microscopically utilizes explosive arc processes, as distinct from the earlier model [Phys. Rev. Lett. 60, 2371 (1988)].

• Received 11 March 1993

DOI:https://doi.org/10.1103/PhysRevLett.71.364