Speaker
Description
Many applications, such as compact accelerators and electron microscopy, demand high
brightness electron beams with small source size and ultra-low-emittance. Diamond emitters
manufactured from the semiconductor process can be employed as such a compact beam source.
The micron-scale pyramid structure of the emitter allows enhancement of the external field
compared to that at the substrate, leading to emission with small beam size. We investigate the
dependence of the field enhancement on the shape of the emitter and the resulting emission
characteristic. The beam dynamics are simulated with the LSP PIC code for extraction of the
macroscopic observables, such as the beam size and divergence. To account for the semiconductor
charge transport in the bulk material and the tunnelling through the surface, a first principle semiclassical
Monte-Carlo (MC) emission model is developed for the diamond pyramid. A nano-scale
tip that may be present on the pyramid resulting from its fabrication process can further enhance
external fields and beam emission, as well as introduces electronic structure size quantization
affecting the transport and tunnelling processes within the tip. These phenomena are accounted for
in our newly developed nanowire emission model.
