| Title |
A CW Normal Conducting RF Cavity for Fast Chirp Control in the LCLS-II |
| Authors |
- M.H. Nasr, P. Emma, S.G. Tantawi
SLAC, Menlo Park, California, USA
|
| Abstract |
The LCLS-II is a high repetition-rate Free-Electron Laser (FEL) facility under construction at SLAC. A new 4-GeV continuous wave (CW) superconducting (SC) L-band linac is being built to provide an electron bunch rate of up to 1 MHz, with bunches rapidly switched between two FEL undulators. It is desirable to provide peak current (i.e., pulse length) control in each FEL independently by varying the RF phase (chirp) prior to the first bunch compressor. However, the high-Q, SCRF, with its 1-ms fill-time, cannot be changed within one bunch spacing (1 us). So to provide a small chirp adjustment from bunch to bunch, we propose a short CW copper RF accelerating cavity, located just after the injector, with < 250-ns fill-time designed to adjust the beam chirp at zero-crossing phase. We examined RF cavity designs spanning RF frequencies from L-band to X-band. We considered both SW and TW structures. We found an optimal solution with 2 cm iris diameter, SW RF cavity, operating at C-band with input power of only 10 kW. If one can afford to operate with smaller diameter, from a wakefield point of view, then similar structure at X-band may require only 500 W with 5 mm iris diameter.
|
| Paper |
download TUPOW030.PDF [0.508 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 |
10-May-16 16:00–18:00 |
| Main Classification |
02 Photon Sources and Electron Accelerators |
| Sub Classification |
A08 Linear Accelerators |
| Keywords |
linac, cavity, controls, FEL, wakefield |
| 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 |
|
