| Title |
Beam Dynamics Observations of Slow Integer Tune Crossing in EMMA |
| Authors |
- J.M. Garland, H.L. Owenpresenter
UMAN, Manchester, United Kingdom
- D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
- B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
|
| Abstract |
When the betatron tune is an integer in a cyclical accelerator, dipole-field errors can drive the coherent addition of betatron amplitude to the bunch eventually causing particle loss. Transverse integer tune crossing in a linear non-scaling FFAG is inevitable due to finite chromaticity. In EMMA (Electron Machine with Many Applications), as many as 6 integers may be crossed is as little as 6 turns at maximum acceleration over the 10 – 20 MeV energy range. This fast integer tune crossing, of the order 1 integer per turn, was shown to have little effect on the coherent amplitude growth and charge loss rate. Slower acceleration inside an RF bucket in EMMA allowed the experimental exploration of slower integer tune crossing speeds, of the order of a factor ten slower. The effect on the coherent oscillation amplitude was observed and the charge loss at integer tune crossings indicated resonant effects on the bunch. Simulations in Zgoubi allowed a more detailed analysis and the mechanism of slower resonance crossing in a non-scaling FFAG is discussed, including the importance of coupled longitudinal-transverse decoherence on the effective emittance.
|
| Paper |
download THPRO084.PDF [2.524 MB / 4 pages] |
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| Conference |
IPAC2014, Dresden, Germany |
| Series |
International Particle Accelerator Conference (5th) |
| Proceedings |
Link to full IPAC2014 Proccedings |
| Session |
Poster Session, Ronaldo Area |
| Date |
19-Jun-14 16:00–18:00 |
| Main Classification |
05 Beam Dynamics and Electromagnetic Fields |
| Sub Classification |
D02 Non-linear Dynamics - Resonances, Tracking, Higher Order |
| Keywords |
simulation, lattice, acceleration, synchrotron, injection |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editors |
Christine Petit-Jean-Genaz (CERN, Geneva, Switzerland); Gianluigi Arduini (CERN, Geneva, Switzerland); Peter Michel (HZDR, Dresden, Germany); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-132-8 |
| Published |
July 2014 |
| Copyright |
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