Computational Screening for Low Emittance Photocathodes
J. T. Paul, R. G. Hennig, A. Galdi, I. V. Bazarov, S. Karkare, H. Padmore
Summary of the screening process. This shows that the screening by our criteria of radioactivity, stability, and bandgap reduces the number of materials from 69,640 to 38,019.
In order to improve beam brightness, we look for currently unused materials that can emit more clustered electrons
Using the MaterialsProject database, we searched over 69,000 materials to identify potential photocathodes. Initial screening criteria reduced this number to approximately 38,000. We then estimated me of these materials using the band structures from MaterialsProject and our calculations, finding a higher density mesh was needed to obtain an accurate estimate.
This project enhances the Center for Bright Beam's objective of striving towards ultralow emittance photocathodes. Particle Accelerators around the world would benefit through improved beam brightness.
The electronic band structure of PbTe. Each letter represents a high symmetry point within reciprocal space. One can see high curvatures in the bands at L points, in-dicating a low MTE due to transverse momentum of the electron.