Title |
Space-Charge Dominated Photoemission in High Gradient Photocathode RF Guns |
Authors |
- Y. Chen, P. Boonpornprasert, J.D. Good, M. Groß, H. Huck, I.I. Isaev, D.K. Kalantaryan, C. Koschitzki, M. Krasilnikov, O. Lishilin, G. Loisch, D. Melkumyan, R. Niemczyk, A. Oppelt, H.J. Qian, Y. Renier, F. Stephan
DESY Zeuthen, Zeuthen, Germany
- H. Chen, Y. C. Du, W.-H. Huang, C.-X. Tang, Q.L. Tian, L.X. Yan
TUB, Beijing, People’s Republic of China
- H. De Gersem, E. Gjonaj
TEMF, TU Darmstadt, Darmstadt, Germany
- M. Dohlus
DESY, Hamburg, Germany
- S. A. Schmid
Institut Theorie Elektromagnetischer Felder, TU Darmstadt, Darmstadt, Germany
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Abstract |
The cathode emission physics plays a crucial role in the overall beam dynamics in the gun. Interplays between intricate emission mechanisms in the cathode vicinity strongly influence the cathode quantum efficiency (QE) and the intrinsic emittance. The presence of strong space-charge effects in high gradient RF guns further complicates the emission process. A proper modeling of photoemission and a careful treatment of the space-charge contribution is thus of great necessity to understanding the formation of the beam slice emittance. In this article, emission measurements are carried out using the L-band cesium-telluride photocathode RF gun at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) and the S-band copper photocathode RF gun at Tsinghua University. Following the Dowell model a simple so-called space-charge iteration approach is developed and used to determine the QE through temporal and spatial-dependent electromagnetic fields. An impact of the space-charge cooling on the thermal emittance is presented. Measurement data are shown and discussed in comparisons to preliminary simulation results.
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Paper |
download THPO116.PDF [1.116 MB / 4 pages] |
Slides |
download THPO116_TALK.PDF [6.249 MB] |
Poster |
download THPO116_POSTER.PDF [3.157 MB] |
Export |
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Conference |
LINAC2018 |
Series |
Linear Accelerator Conference (29th) |
Location |
Beijing, China |
Date |
16-21 September 2018 |
Publisher |
JACoW Publishing, Geneva, Switzerland |
Editorial Board |
Guoxi Pei (IHEP, Beijing, China); Volker RW Schaa (GSI, Darmstadt, Germany); Yong Ho Chin (KEK, Tsukuba, Japan); Shinian Fu (IHEP, Beijing, China); Ning Zhao (IHEP, Beijing, China) |
Online ISBN |
978-3-95450-194-6 |
Online ISSN |
2226-0366 |
Received |
11 September 2018 |
Accepted |
21 September 2018 |
Issue Date |
18 January 2019 |
DOI |
doi:10.18429/JACoW-LINAC2018-THPO116 |
Copyright |
Published by JACoW Publishing under the terms of the Creative Commons Attribution 3.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI. |
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