Rapid Mapping of Photocathode Quantum Efficiency: A Magnetized Electron Beam Imaging Approach

Abstract

Quantum efficiency (QE) is a key property of photocathodes, and its uniformity is essential for producing high-brightness electron beams. Cathode imaging provides an \textit{in-situ} and real-time approach for QE mapping, but in RF guns, a high charge per bunch is often needed to obtain a sufficient signal-to-noise ratio. Under such conditions, space charge effects can significantly degrade the imaging resolution and may even make point-to-point cathode imaging ineffective. In this paper, we propose a novel cathode imaging method based on a magnetized electron beam. Its feasibility is examined through theoretical analysis and beam dynamics simulations. The results show that the proposed method enables point-to-point cathode imaging in the ten picocoulomb charge regime. For a 10 pC, 3ps beam with a cathode magnetic field of 1200 Gauss, simulations indicate an imaging resolution of 11 um, representing nearly an order-of-magnitude improvement over the non-magnetized beam method.

Ultralow Mean Transverse Energy and High Quantum Efficiency Cryogenic Bialkali Photocathode for MHz-Repetition-Rate Electron Sources
D. Wang, S. Liu, J. Liu +15
arXiv20 Sep 2026PreprintarXiv licenceFull textApplied physics & instrumentationarXiv
Development of a continuous-wave photocathode very-high-frequency electron gun for S³FEL
Lianmin Zheng, Yitong Duan, Yuanyuan Qin +11
arXiv6 Oct 2026PreprintarXiv licenceFull textApplied physics & instrumentationarXiv
Cryogenic Enhancement of Electron Spin Polarization from a Strained GaAs/GaAsP Superlattice Photocathode
Matt Grau, Colin Kirk, Greg Blume +7
arXiv1 Sep 2026PreprintarXiv licenceFull textApplied physics & instrumentation Condensed matterarXiv
Electron escape probability in high-efficiency photocathodes measured by reverse-injection photovoltage
S. A. Rozhkov, D. A. Kustov, V. V. Bakin +4
arXiv16 Sep 2026PreprintarXiv licenceFull textCondensed matterarXiv
Quantum-Geometric Meissner Effect in Magnetized Color Superconductors
Kazuya Mameda, Noriyuki Sogabe
arXiv7 Sep 2026PreprintCC BY 4.0Full textCondensed matter High-energy & particle physicsarXiv

Cite

BibTeX RIS

BibTeX

@misc{liu2026rapid,
  title = {{Rapid Mapping of Photocathode Quantum Efficiency: A Magnetized Electron Beam Imaging Approach}},
  author = {Yihan Liu and Lianmin Zheng and Yingchao Du},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.02070},
  eprint = {2609.02070},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.02070},
}

RIS

TY  - UNPB
TI  - Rapid Mapping of Photocathode Quantum Efficiency: A Magnetized Electron Beam Imaging Approach
AU  - Yihan Liu
AU  - Lianmin Zheng
AU  - Yingchao Du
PY  - 2026
DA  - 2026/09/02
PB  - arXiv
DO  - 10.48550/arxiv.2609.02070
UR  - https://arxiv.org/abs/2609.02070
AB  - Quantum efficiency (QE) is a key property of photocathodes, and its uniformity is essential for producing high-brightness electron beams. Cathode imaging provides an \textit{in-situ} and real-time approach for QE mapping, but in RF guns, a high charge per bunch is often needed to obtain a sufficient signal-to-noise ratio. Under such conditions, space charge effects can significantly degrade the imaging resolution and may even make point-to-point cathode imaging ineffective. In this paper, we propose a novel cathode imaging method based on a magnetized electron beam. Its feasibility is examined through theoretical analysis and beam dynamics simulations. The results show that the proposed method enables point-to-point cathode imaging in the ten picocoulomb charge regime. For a 10 pC, 3ps beam with a cathode magnetic field of 1200 Gauss, simulations indicate an imaging resolution of 11 um, representing nearly an order-of-magnitude improvement over the non-magnetized beam method.
ER  -

Abstract

Related

Cite