| Title |
LLRF Control of High Loaded-Q Cavities for the LCLS-II |
| Authors |
- C. Serrano, L.R. Doolittle, G. Huang, A. Ratti
LBNL, Berkeley, California, USA
- S. Babel, M. Boyes, B. Hong
SLAC, Menlo Park, California, USA
- R. Bachimanchi, C. Hovater
JLab, Newport News, Virginia, USA
- B.E. Chase, E. Cullerton, J. Einstein
Fermilab, Batavia, Illinois, USA
|
| Abstract |
The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW Superconducting Radio Frequency (SCRF) linac. The nature of the machine places stringent requirements in the Low-Level RF (LLRF) system, expected to control the cavity fields within 0.01 degrees in phase and 0.01% in amplitude, which is equivalent to a longitudinal motion of the cavity structure in the nanometer range. This stability has been achieved in the past but never for hundreds of superconducting cavities in Continuous-Wave (CW) operation. The difficulty resides in providing the ability to reject disturbances from the cryomodule, which is incompletely known as it depends on the cryomodule structure itself (currently under development at JLab and Fermilab) and the harsh accelerator environment. Previous experience in the field and an extrapolation to the cavity design parameters (relatively high Q_{L}c≈ 4×10⁷ , implying a half-bandwidth of around 16 Hz) suggest the use of strong RF feedback to reject the projected noise disturbances, which in turn demands careful engineering of the entire system.
|
| Funding |
This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515 |
| Paper |
download WEPOR042.PDF [1.104 MB / 3 pages] |
| Export |
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| Conference |
IPAC2016, Busan, Korea |
| Series |
International Particle Accelerator Conference (7th) |
| Proceedings |
Link to full IPAC2016 Proccedings |
| Session |
Poster Session |
| Date |
11-May-16 16:00–18:00 |
| Main Classification |
06 Beam Instrumentation, Controls, Feedback and Operational Aspects |
| Sub Classification |
T27 Low Level RF |
| Keywords |
cavity, LLRF, controls, feedback, linac |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Christine Petit-Jean-Genaz (CERN, Geneva, Switzerland); Dong Eon Kim (PAL, Pohang, Republic of Korea); Kyung Sook Kim (PAL, Pohang, Republic of Korea); In Soo Ko (POSTECH, Pohang, Republic of Korea); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-147-2 |
| Published |
June 2016 |
| Copyright |
|
