IPAC2014 - Classification: 03 Particle Sources and Alternative Acceleration Techniques / A12 FFAG

Paper	Title	Page
TUYB01	Vertical Orbit-excursion Fixed Field Alternating Gradient Accelerators (V-FFAGs) and 3D Cyclotrons	956
	S.J. Brooks BNL, Upton, Long Island, New York, USA
	FFAGs with vertical orbit excursion (VFFAGs) provide a promising alternative design for rings with fixed-field (e.g. superconducting) magnets. They have a vertical magnetic field component that increases with height in the vertical aperture, yielding a skew quadrupole focussing structure. Scaling type VFFAGs have fixed tunes and no intrinsic limitation on momentum range; they are also isochronous in the ultra-relativistic limit. Extending isochronism to lower velocities requires a slanted orbit excursion: a three-dimensional analogue of a spiral sector cyclotron from 40 to 1500MeV is developed, which is flat at low energies and acquires a slope as the protons become relativistic. This provides more stable tunes than a comparable planar cyclotron. Such machines are promising future candidates for nuclear transmutation using high average power CW beams at ~GeV energies.
	Slides TUYB01 [16.187 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUYB01
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TUPRI009	Study of Resonance Crossing in Non-scaling FFAGs using the S-POD Linear Paul Trap	1571
	D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom K. Fukushima, K. Ito, K. Moriya, H. Okamoto, T. Okano HU/AdSM, Higashi-Hiroshima, Japan
	Experiments on EMMA have shown that with rapid acceleration (~10 turns) a linear non-scaling FFAG can accelerate through several integer tunes without detrimental effects on the beam [1]. Proton and ion applications such as hadron therapy will necessarily have a slower acceleration rate, so their feasibility depends on how harmful resonance crossing is in this regime. A simple and useful tool to answer such fundamental questions is the S-POD linear Paul trap at Hiroshima University, which can be set up to simulate the dynamics of a beam in an FFAG. We report here results of experiments to explore different resonance crossing speeds, quantify beam loss and study nonlinear effects. We also discuss the implications of these experimental results in terms of limits on acceptable acceleration rates and alignment errors. [1] S.Machida et al, Nature Physics, N8, 243-257 (2012)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI009
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TUPRI013	Dynamic Aperture Studies of the nuSTORM FFAG Ring	1574
	R. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier UMAN, Manchester, United Kingdom K.M. Hock Cockcroft Institute, Warrington, Cheshire, United Kingdom J.-B. Lagrange, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: Research supported by STFC grant number ST/K002503/1 "Racetrack FFAGs for medical, PRISM and energy applications". FFAG rings with a racetrack configuration are very promising as their flexible design allow for dedicated spaces for injection/extraction, RF cavities etc. A racetrack FFAG is considered as an option for the nuSTORM facility, which aims to deliver neutrino beams produced from the decay of muons stored in a ring with long sections pointing towards detectors. In this paper we discuss the definition of dynamic aperture in these machines and use the PyZgoubi framework to compute the many turn motion in the nuSTORM ring. The roles of machine imperfections and symmetry are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI013
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Vertical Orbit-excursion Fixed Field Alternating Gradient Accelerators (V-FFAGs) and 3D Cyclotrons

956

S.J. Brooks
BNL, Upton, Long Island, New York, USA

FFAGs with vertical orbit excursion (VFFAGs) provide a promising alternative design for rings with fixed-field (e.g. superconducting) magnets. They have a vertical magnetic field component that increases with height in the vertical aperture, yielding a skew quadrupole focussing structure. Scaling type VFFAGs have fixed tunes and no intrinsic limitation on momentum range; they are also isochronous in the ultra-relativistic limit. Extending isochronism to lower velocities requires a slanted orbit excursion: a three-dimensional analogue of a spiral sector cyclotron from 40 to 1500MeV is developed, which is flat at low energies and acquires a slope as the protons become relativistic. This provides more stable tunes than a comparable planar cyclotron. Such machines are promising future candidates for nuclear transmutation using high average power CW beams at ~GeV energies.

Slides TUYB01 [16.187 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUYB01

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI009

Study of Resonance Crossing in Non-scaling FFAGs using the S-POD Linear Paul Trap

1571

D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
K. Fukushima, K. Ito, K. Moriya, H. Okamoto, T. Okano
HU/AdSM, Higashi-Hiroshima, Japan

Experiments on EMMA have shown that with rapid acceleration (~10 turns) a linear non-scaling FFAG can accelerate through several integer tunes without detrimental effects on the beam [1]. Proton and ion applications such as hadron therapy will necessarily have a slower acceleration rate, so their feasibility depends on how harmful resonance crossing is in this regime. A simple and useful tool to answer such fundamental questions is the S-POD linear Paul trap at Hiroshima University, which can be set up to simulate the dynamics of a beam in an FFAG. We report here results of experiments to explore different resonance crossing speeds, quantify beam loss and study nonlinear effects. We also discuss the implications of these experimental results in terms of limits on acceptable acceleration rates and alignment errors.
[1] S.Machida et al, Nature Physics, N8, 243-257 (2012)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI009

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI013

Dynamic Aperture Studies of the nuSTORM FFAG Ring

1574

R. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier
UMAN, Manchester, United Kingdom
K.M. Hock
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J.-B. Lagrange, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: Research supported by STFC grant number ST/K002503/1 "Racetrack FFAGs for medical, PRISM and energy applications".
FFAG rings with a racetrack configuration are very promising as their flexible design allow for dedicated spaces for injection/extraction, RF cavities etc. A racetrack FFAG is considered as an option for the nuSTORM facility, which aims to deliver neutrino beams produced from the decay of muons stored in a ring with long sections pointing towards detectors. In this paper we discuss the definition of dynamic aperture in these machines and use the PyZgoubi framework to compute the many turn motion in the nuSTORM ring. The roles of machine imperfections and symmetry are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI013

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)