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Experimental reconstruction of source 4D phase space without prior knowledge of transfer matrix

Charles Zhang1,*, Elena Echeverria1, Abigail Flint1, William H. Li2, Christopher M. Pierce3, Alice Galdi4, Chad Pennington5, Adam Bartnik1, Ivan Bazarov1 et al.

Jared Maxson1

  • *Contact author: cz266@cornell.edu
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Phys. Rev. Accel. Beams 29, 074501 – Published 21 July, 2026

DOI: https://doi.org/10.1103/7vk2-ktxk

Abstract

We experimentally demonstrate a method for reconstructing the transverse 4D phase space of an electron beam at the time of emission from downstream diagnostics of the 4D phase space. This method does not rely on detailed knowledge of the beamline transport, besides assuming that linearity and symplecticity are satisfied. We apply this method to measure the transverse position and momentum phase space of electrons emitted from a spatially structured alkali-antimonide cathode. This method can uncover local correlations between emission location and momentum spread. We formulate this method analytically and investigate resolution limits.

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Phys. Rev. Accel. Beams 29, 074501– Published 21 July, 2026
  • Received 6 October 2025
  • Accepted 19 May 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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