Field emission cathode
Euclid TechLabs offers Nitrogen-doped Ultra-nano-crystalline diamond (UNCD) field emission cathodes (FEC) that deliver significant average currents in mA range at high beam quality.
Microwave electron guns, best known within the realm of X-ray sources, provide a higher current and much higher quality electron beams than conventional DC guns. Beams of this sort are also used in free-electron lasers, synchrotrons, linear colliders and wakefield accelerator schemes.
But for two traditional electron emission mechanisms involved — laser irradiation of materials (photocathodes) and heating of materials (thermionic cathodes) — tend to be complex, bulky or extremely expensive. To simplify the process we turned to a third electron emission mechanism — field emission — to create a plug-and-play solution based on ultra-nanocrystalline diamond (UNCD) originally introduced at Argonne National Lab.
Due to the unique carbon bonding configuration within the few-atoms-wide grain boundaries surrounded by nano-sized UNCD grains, UNCD cathodes yield very high field enhancement naturally and performs better even in planar configurations, unlike other diamond films, which need to be shaped into high aspect ratio structures to locally enhance electric field.
Importantly, UNCD survived under harsh conditions in the RF gun without noticeable degradation for an extended period of time.