Speaker
Description
The thermal limit of the intrinsic emittance of photocathodes represents an important property
to measure experimentally and to understand theoretically. Detailed measurements of intrinsic
emittance have become possible in momentatron experiments. Moreover, recent developments
in material design have allowed growing photoemissive layers with controlled surface roughness.
Although analytical formulations of the effects of roughness have been developed, a full theoretical
model and experimental verification are lacking. We aim to bridge this gap by developing realistic
models for different materials in the three-dimensional VSim particle-in-cell code. We have recently
implemented modeling of electron photo-excitation, transport, and emission from photoemissive
layers grown on a substrate. We report results from simulations with these models on electron
emission from antimony and gold. We consider effects due to surface roughness, density of states,
photoemissive layer thickness, and how they affect the spectral response of quantum yield and
intrinsic emittance.
