| Paper | Title | Page |
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| TUPAN001 | Analytic Models for Quadrupole Fringe-Field Effects | 1386 |
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Funding: TRIUMF receives federal funding via a contribution agreement through the National Research Council of Canada The linear-field non-scaling FFAG lattices originally proposed for multi-GeV muon acceleration are now being modified for application to order 100 MeV/u proton or carbon medical applications. The momentum range is large and the chromatic tune variation is significant. In the medical case, the time of flight variation is immaterial but the issue of resonance crossing is more acute owing to the much lower rate of energy gain. Magnets with non-normal entry/exit faces are considered as means to reduce the tune variation. Thus one is motivated to study fringe fields and their effects. We make a brief study of dipole and quadrupole magnets with normal and rotated entry/exit faces. For the artificial case of a cosine-squared fall off in the quadrupole field, analytic results are obtained which though approximate are superior to numerical integration. This property is achieved by insisting that the error in the equation of motion is zero and the determinant is unity at the entry, exit and centre of the fringe field. |
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| THPMN103 | New Nonscaling FFAG for Medical Applications | 2951 |
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Funding: Work supported by by the Fermilab Research Association, Inc., under contract DE-AC02-76CH00300 with the U. S. Department of Energy. Fixed Field Alternating Gradient (FFAG) machines have been the subject of recent international activity due to their potential for medical applications and accelerator-based technologies. In particular, nonscaling FFAGs (where the optics are not constant and therefore do not scale with momentum) stand to offer the high current advantage of the cyclotron combined with the smaller radial aperture of the synchrotron plus variable extraction energy. Here, a hybrid design for a nonscaling FFAG accelerator has been invented which uses both edge and alternating-gradient focusing principles applied to a combined-function magnet applied in a specific configuration to stabilize tunes through an acceleration cycle which extends over a factor of 2-6 in momentum. Using normal conducting magnets, the final, extracted energy from this machine attains 400 MeV/nucleon and a normalized emittance of ~10 - 20π, and thus supports a carbon ion beam in the energy range of interest for cancer therapy. |
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| THPAN109 | A New Lattice Design for a 1.5 TeV CoM Muon Collider Consistent with the Tevatron Tunnel | 3483 |
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| A recent effort is underway to design an efficient match of a Muon Collider to the Fermilab site, potentially using the Tevatron tunnel after decommissioning. This work represents a new design for such a collider with emphasis on shortened IR and systematic high-order correction and dynamics studies. With a 1 cm β*, simultaneous control of geometric and chromatic aberrations is critical and can only be achieved through the deliberate addition of nonlinear fields in the Interaction Region itself. This work studies both the correction schemes and the unavoidable impact of high-order correctors – sextupoles, octupoles and even duodecapoles – located in the Interaction Region close to the low-beta quadrupoles or focusing elements. This study proposes and systematically addresses the aberrations for different systems of nonlinear correctors and optimizes performance of an advanced IR. | ||
| FRPMS009 | Calculating the Nonlinear Tune Shifts with Amplitude using Measured BPM Data | 3889 |
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| An algorithm is proposed to calculate the approximate tune shifts with amplitude using only the linear transfer map of a circular accelerator and with little or no information on higher order nonlinearities. To extract information about the nonlinear dynamics, the decay rate of the average amplitude of the particle distribution after an instantaneous transversal horizontal or vertical kick is used. This method works when strong low-order resonances are not present, that is where the linear lattice rather than the nonlinear driving terms dominates the machine dynamics. Nonlinear normal form transformation and differential algebra methods are employed to establish the connection between measurement results and the nonlinear tune shifts with amplitude. Proposed algorithm is applicable to a wide range of circular accelerators. |