| Title |
Long Term Beam Phase Monitoring Based on HOM Signals in SC Cavities at FLASH |
| Authors |
- J.H. Wei
USTC/NSRL, Hefei, Anhui, People’s Republic of China
- N. Baboi
DESY, Hamburg, Germany
- L. Shi
PSI, Villigen PSI, Switzerland
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| Abstract |
The accelerating RF fields in superconducting cavities must be controlled precisely in FEL (Free Electron Laser) facilities to avoid beam energy spread and arrival time jitter. Otherwise the beam quality is degraded. The LLRF (Low Level Radio Frequency) system controls the RF field and provides a highly stable RF reference. A new type of beam phase determination technique based on beam-excited HOMs (Higher Order Modes) in cavities has been implemented. The two special couplers installed at both ends of each cavity, pick up the signals containing both the leakage of the accelerating field and the HOM signals. Therefore the signals can be used to calculate the beam phase directly with respect to the RF phase. We analysed the factors which may affect the result of the beam phase on a long-term based on an experimental platform at FLASH. Some phase drifts between the HOM-BPhM (Beam Phase Monitor) and the LLRF system phase measurement were observed and the reason will be further studied.
|
| Paper |
download WEPA09.PDF [0.522 MB / 4 pages] |
| Poster |
download WEPA09_POSTER.PDF [1.720 MB] |
| Export |
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| Conference |
IBIC2018 |
| Series |
International Beam Instrumentation Conference (7th) |
| Location |
Shanghai, China |
| Date |
09-13 September 2018 |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editorial Board |
Volker RW Schaa (GSI, Darmstadt, Germany) |
| Online ISBN |
978-3-95450-201-1 |
| Received |
05 September 2018 |
| Accepted |
13 September 2018 |
| Issue Date |
29 January 2019 |
| DOI |
doi:10.18429/JACoW-IBIC2018-WEPA09 |
| 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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