PHYSICS OF ELECTRON-EMISSION FROM METAL-DIELECTRIC CATHODES

The present paper gives a description of the metal-dielectric cathode interaction. There is an explosive electron emission on the cathodes, that occurs through explosions of the metal microprotrusions at so-called triple points (metal-dielectric-vacuum). The current of a vacuum discharge over the dielectric surface plays an initiating role. Such a mechanism of emission operates in low-voltage ferroelectric cathodes, in cathodes of long service in high-power pulse repetitive accelerators, as well as in the cathodes used in focusing high power electron beams.