| Paper | Title | Page |
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| TUPP048 | Collective Effects in the EMMA Non-scaling FFAG | 1652 |
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| EMMA is an electron machine to study beam dynamics in a linear nonscaling FFAG. We wish to verify that the behavior predicted by the theory and simulation is correct. In particular, we will study, with large emittance beams, a novel accelerating mode outside an rf bucket, and the effects of crossing "resonances." In EMMA, some collective effects become a concern even though the beam stays in the ring for only 10 to 20 turns. We report studies of direct and image space charge, beam loading, and other collective effects with a tracking simulation. Space charge effects, already potentially significant in EMMA, are enhanced by the fact that the beam passes through the beam pipe off-center. There is some possibility of a negative mass instability for some operation modes. We will show several 3D simulation results for space charge and beam loading effects and pure longitudinal simulation for the negative mass instability. | ||
| WEPP116 | Muon Decay Ring Study | 2770 |
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Three different muon decay ring configurations are being considered for a neutrino factory. A racetrack design is the current ISS baseline (as it allows greater flexibility in the choice of detector sites) but triangular and bow-tie rings have advantages in neutrino production rates*. Using tracking code simulations, a study of the latter two designs is carried out. Since spin depolarisation measurements have been proposed for muon energy calibration**, spin tracking is included in this study. Dynamic aperture is important and is also calculated.
*International Scoping Study report, 2006. |
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| THPP005 | Orbit Distortion and its Correction in a Non-scaling FFAG | 3383 |
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| The wide variation in betatron tune over a rapid acceleration time presents particular difficulties in orbit correction in a non-scaling FFAG. Due to the fact that the phase advance between an error source and the corrector magnets varies during acceleration, and assuming that the corrector magnets' strengths must be constant during the short acceleration period, it is clear that conventional harmonic correction is ineffective. We propose a method to determine the magnet and BPM misalignments in a non-scaling FFAG. By running the beam at fixed energy over many turns, and assuming no other error sources exist, the BPM measurements allow the misalignments to be calculated (assuming that there are as many BPMs as error sources). We show that it is also possible to calculate the BPM misalignment error if the beam is run at two fixed energies. This is due to a characteristic property of non-scaling FFAGs - the variation of the phase shift, and hence the response of the BPM measurements to magnet misalignments, with momentum. Having estimated the magnet misalignments, a local correction is made and a tracking study carried out to calculate the reduction in orbit distortion that results. | ||
| THPP004 | EMMA - the World's First Non-scaling FFAG | 3380 |
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| EMMA - the Electron Model of Many Applications - is to be built at the STFC Daresbury Laboratory in the UK and will be the first non-scaling FFAG ever constructed. EMMA will be used to demonstrate the principle of this type of accelerator and study their features in detail. The design of the machine and its hardware components are now far advanced and construction is due for completion in summer 2009. |