Pulsed T-F Emission Electron Projection Microscopy

Pulse electronic techniques extend the advantages of field emission microscopy to desirable experimental conditions not attained with steady-state fields. A visually continuous ``motion picture'' emission pattern enhances the study of transient cathode mechanisms while holding negligible the adverse effects of large electrostatic forces on both cathode stability and mechanisms under study. Observation is extended to elevated cathode temperatures, to higher environmental gas pressures, and to low tensile strength cathode materials; at the same time, excellent cathode electrical stability is maintained. Several mechanisms are illustrated, including condensation, volume diffusion, surface migration, and cathode blunting.