D. Marx, J. Giner Navarro, D. Cesar, J. Maxson, B. Marchetti, R. Assmann, and P. Musumeci

What are the overall findings of the research?

A detailed algorithm for the single-shot reconstruction of the 4D phase space distribution using metal grids, with the direct measurement of the core emittance, provides valuable insights in the production of ultra-bright electron beams. The technique has been benchmarked experimentally at UCLA for emittances in the nm-level. The article reveals important advantages of TEM grid technique based on the shadow projection of thin bars in order to fully describe the properties of very low charge (sub-pC), ultrahigh brightness electron beams.

What overall goal does this result advance?
The results of this research will be beneficial in the production of ultralow emittance photocathodes and beam transport.

A graph showing cumulative distribution of beam charge vs emittance (blue), and core emittance extrapolation (green). The y-axis is labeled with "Fractional Charge", and increases along the x-axis (m2 rad2)

What potential applications could benefit from this advancement?

The diagnostics technique have applications in assessing the performance of new photocathodes, characterizing the beam in very low charge experiments, and correcting undesired coupling in the beam optics due to spurious field components.

Full publication:

https://journals.aps.org/prab/abstract/10.1103/PhysRevAccelBeams.21.102802