Thestructures are of two general types, one employing radial sectors and the other a spiral sector pattern. Fundamental limit of nonscaling fixed field alternating gradient accelerators s. Fixedfield alternatinggradient accelerators science. Scott berg, morteza aslaninejad, jaroslaw pasternak, holger witte, neil bliss, michael cordwell, thomas jones, alan muir, david kelliher and shinji machida. Fixed field alternating gradient accelerators overview, status. We would like to show you a description here but the site wont allow us.
A more compact accelerator design would allow multiple accelerators to be combined to improve reliability. One such accelerator is the nonscaling fixed field alternating gradient nsffag accelerator, and it is a very promising candidate, but noone has yet built such a machine, and there are many technical challenges to be overcome before such a machine could be used commercially. The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy the use of protons and other light ions to treat some forms of cancer is described. Scaling fixedfield alternatinggradient accelerators with. These notes provide an overview of fixed field alternating gradient ffag accelerators for medical applications.
Conceptual design of a nonscaling fixed field alternating. Fixed field alternating gradient accelerator with small orbit. Move to fixed field alternating gradient accelerator. Lasers in combined experiments alice accelerator 7 is used as an injector to the emma ring. The nonscaling fixed field alternating gradient accelerator. An opportunity is arising which could allow the nsffag to be used. Information about the openaccess article fixed field alternating gradient accelerator with small orbit shift and tune excursion in doaj. The cbeta project is currently in the commissioning stage and some of the beam optics of the accelerator has be done using lampmagnet methods to describe the fields of the ffag magnets. Fixed field alternating gradient accelerators overview. The concept of a fixed field alternating gradient ffag accelerator was invented in the 1950s.
The paper describes an accelerator scenario of a pulsed spallation neutron source made of an induction linac injecting into a fixed field alternating gradient accelerator ffag. The accelerator is called a nonscaling, fixed field alternating gradient nsffag accelerator, and will accelerate both protons and carbon ions to energies required for clinical use. An introduction to fixed field alternating gradient. In a fixed field alternating gradient ffag accelerator, eliminating pulsed magnet operation permits rapid acceleration to synchrotron energies, but with a. Sheehy university of oxford, uk abstract these notes provide an overview of fixed field alternating gradient ffag accelerators for medical applications. Citeseerx fixed field alternating gradient particle. International workshop on fixed field alternating gradient. Although many studies were carried out up to the late 1960s, there has been relatively little progress until recently, when it. Superconducting magnet design for fixedfield alternatinggradient ffag accelerator showing 14 of 8 pages in this article. The field is generated by equally spaced magnets around the circumference and varies from a maximum of 4. The firstmentioned type is insomewayssimplerandeasier to construct, while the second appears to permit a smaller accelerator for a given energy. Alternating gradient ag focusing1 provides a high degree of stability for both the radial and vertical modes of betatron. A nonscaling fixed field alternating gradient nsffag accelerator was constructed, which employs conventional quadrupoles.
Alternating gradient is a focusing scheme with both sign of gradient magnets, focusing and defocusing elements. The cbeta project is currently in the commissioning stage and some of the beam optics of the accelerator has be done using. Thus, ffa accelerators combine the cyclotrons advantage of. Design study of a nonscaling fixedfield alternating. The cbeta project 1 is the first and unique of its kind electron accelerator which combines two accelerator concepts together. Amplitudedependent orbital period in alternating gradient. If the address matches an existing account you will receive an email with instructions to reset your password. The motivations underlying the proposal deal with the concern of removing technical risks peculiar to other scenarios involving rf linacs, synchrotrons and accumulator rings, which originate, for example, from the. The pyzgoubi framework and the simulation of dynamic aperture. We present a design for a nonscaling fixedfield alternating gradient accelerator ffag for proton beams of 250 mev. It is based on optics that produce approximate scaling properties.
The lattice of a fixed field alternating gradient ffag accelerator 1 consists of ma ny identical small cells with a minimum focusing structure such as fodo, doublet, triplet, or pumplet 2, where f is a focusing magnet, d is a defocusing magnet and o is a drift space in between. This thesis examines the use of a fixed field alternating gradient ffag accelerator as the proton driver. This scaling ffag accelerator combines reverse bending magnets of the radial sector type and a spiral edge angle of the spiral sector type to ensure sufficient vertical focusing without relying on. Ffags are compact, and can simultaneously achieve higher energies than a cyclotron at higher repetition rates than a synchrotron. Owing to the fixed magnetic field as in a cyclotron, the ffag accelerator can accelerate particles very rapidly, which results in high currents, while the magnetic gradient as. Design of a novel fixed field alternating gradient ffag. Progress on simulation of fixed field alternating gradient. We measured orbital period in a linear nonscaling fixed field alternating gradient accelerator, which is a candidate for muon acceleration, and compared it with the theoretical prediction. Dec 29, 2004 fixed field alternating gradient accelerator abstract analytical expressions for the equilibrium orbits and the betatron oscillations are developed and are compared with numerical results obtained by digital computation. Use rf bucket to capture a beam in longitudinal plane like a synchrotron.
A fixed field alternating gradient accelerator with long. Although many studies were carried out up to the late 1960s, there has been relatively little progress until recently, when it received widespread attention as a type of accelerator suitable for very fast. A nonscaling fixed field alternating gradient accelerator. Application of alternating gradient focusing, however, can keep both modes of betatron oscillation stable even with the rapid radial change of magnetic field. Fixedfield alternatinggradient accelerators researchgate. Tunestabilized, nonscaling, fixedfield, alternating. We have developed a technique that produces from the numerical field map, a dynamical map for a particle. Design of a nonscaling fixed field alternating gradient. Gradient is determined by focusing condition, not by isochronous condition. Fixed field alternating gradient accelerators have been realised in recent decades thanks partly to computational power, enabling detailed design and simulation prior to construction. A fixed field alternating gradient accelerator ffa is a circular particle accelerator concept on which development was started in the early 50s, and that can be characterized by its timeindependent magnetic fields fixed field, like in a cyclotron and the use of strong focusing alternating gradient, like in a synchrotron. Starting from first principle the hamiltonian formalism for the description of the dynamics of. The possible demerit is the beam instability caused by the variable focusing strength when the orbit radius of the beam changes. Normalconducting scaling fixed field alternating gradient.
The nonscaling fixed focus alternating gradient ffag accelerator is of strong interest for doe facilities and commercial applications as a less expensive, faster cycling, and morereadilyoperable device. Terwilliger, midwestern universities research association april 26, 1956 i. The non scaling fixed field alternating gradient nsffag. Jan 10, 2012 in a fixed field alternating gradient ffag accelerator, eliminating pulsed magnet operation permits rapid acceleration to synchrotron energies, but with a much higher beampulse repetition rate. We present a design of nonscaling fixed field alternating gradient accelerators ffag minimizing the dispersion action function h. View academics in fixed field alternating gradient accelerator on academia. Fixed field alternating gradient ffag accelerator part i. Both techniques are applied in fixed field alternating gradient accelerators ffags, which were intensively studied in the 1950s and 60s with electron models. Cyclotrons and fixedfield alternatinggradient accelerators. A nonscaling fixed field alternating gradient accelerator for the final acceleration stage of the international design study of the neutrino factory.
This thesis describes the design a novel type of particle accelerator for charged particle therapy. These orbits may all be in an annular ring, as in a synchrotron or betatron. These machines contain stable equilibrium orbits for all particles from the injection energy to the output energy. A new design principle of a nonscaling fixed field alternating gradient accelerator is proposed. Fundamental limit of nonscaling fixedfield alternating. A large field index k is chosen to squeeze the orbit shift as much as possible by setting the betatron oscillation frequency in the second stability region of hills equation. No ramping of magnets like a cyclotron increase repetition as much as possible by sweeping rf.
The workshop is organized by institute for integrated radiation and nuclear science, kyoto university kurns. The page was first moved to fixed field alternating gradient accelerator after consensus was reached, then moved again to regularize the capitalization. Pdf these notes provide an overview of fixed field alternating gradient ffag accelerators for medical applications. The annual workshop on the fixed field alternating gradient accelerators ffa will be held at clock tower centennial hall, yoshida campus, kyoto university, kyoto, japan, for 10th14th september, 2018. Fixed field alternating gradient accelerator with small. The general coil design employs cryostable magnets wound with aluminum stabilized superconductor. They also represent a possible active element for an accelerator driven subcritical reactor adsr. The motivations underlying the proposal deal with the concern of removing technical risks peculiar to other scenarios involving rf linacs, synchrotrons and accumulator rings, which originate, for example.
The ffag accelerator requires static fields that increase with radius along the accelerator midplane according to b bsub 0 rrsub 0sup. A compact, isochronous fixed field, gradient ion accelerator, 1. We show the design results for the nonscaling ffag and discuss the optimization of the lattice. We show the design results for the nonscaling ffag and discuss the optimization of the lattice parameters. Fixedfield alternating gradient accelerator wikipedia. Fixed field alternating gradient ffag accelerators use a magnetic field that does not change with time, but does contain field gradients along the radial direction. The fixed field alternating gradient ffag accelerator, conceived independently by ohkawa, kolomensky and symon in the early 1950s,, is a ring particle accelerator which differs from a cyclotron in that the field gradient alternates in sign during a particle orbit, giving strong focusing in both planes of transverse motion. Lee department of physics, indiana university, bloomington, indiana 47405, usa gsi, darmstadt, d64291, germany received 14 march 2006. This thesis examines the use of a fixedfield alternatinggradient ffag accelerator as the proton driver. A fixed field alternating gradient accelerator ffag accelerator is a type of circular particle accelerator that uses timeindependent fixed magnetic fields and strong focusing. Evaluation of asymmetric quadrupoles for a nonscaling fixed. The pyzgoubi framework and the simulation of dynamic. The fixed field alternating gradient ffag accelerator, proposed independently by ohkawa, kolomensky and symon in the early 1950s, employs an annular ring of magnets with alternating field. Citeseerx document details isaac councill, lee giles, pradeep teregowda.
A novel scaling type of fixed field alternating gradient ffag accelerator is proposed that solves the major problems of conventional scaling ffags. Focusing is similar to synchrotron use alternating gradient focusing in transverse plane like a synchrotron. Emma has a compact linear lattice, in which the effects of magnet fringe fields need to be modelled carefully. For this design, a radial sector type ffag that has a triplet structure of focusingdefocusingfocusing magnets is investigated as a machine to provide the proton beam. Although many studies were carried out up to the late 1960s, there has been relatively little.
Pdf dynamics of particles in non scaling fixed field. The work is undertaken as part of the pamela project. Tygier university of manchester, manchester, m 9pl, united kingdom and cockcroft institute. Fixed field alternating gradient accelerator approach. Superconducting magnet design for fixedfield alternating.
Pulsed spallation neutron source with an induction linac and. The fixed field alternating gradient ffag accelerator, proposed independently by ohkawa, kolomensky and symon in the early 1950s, employs an annular ring of magnets with alternating field gradients. This patent application claims the priority and benefit of u. Dynamics of particles in non scaling fixed field alternating gradient accelerators.
This project will investigate the feasibility of this concept and plan for the construction of a scaled electron prototype. High current proton fixedfield alternatinggradient. Phy684, sbu suny, 2018 2 contents 1 introduction 5 2 mura electron ffags 7. High current proton fixed field alternating gradient accelerator designs a thesis submitted to the university of manchester for the degree of doctor of philosophy phd in the faculty of engineering and physical sciences samuel c t tygier school of physics and astronomy 2012. High current proton fixed field alternating gradient accelerator designs a thesis submitted to the university of manchester for the degree of doctor of philosophy phd in the faculty of engineering and physical sciences samuel c t tygier school of physics and. Fixed field alternating gradient shinji machida astec, stfc rutherford appleton laboratory, didcot, united kingdom abstract the concept of a fixed field alternating gradient ffag accelerator was invented in the 1950s. The energy delivered by this injector can vary from a 10 to 20 mev single bunch train with a bunch charge of 16 to 32 pc at a rate of 1 to 20 72 james k. A numerical magnetic field map can be generated from magnet measurements or magnet design software. We present the basic principles of a nonscaling ffag lattice and discuss optimization strategies so that one can accelerate over a broad range of momentum with reasonable apertures. Academics in fixed field alternating gradient accelerator. One of the reasons not to choose a more complicated.
Dynamics of particles in non scaling fixed field alternating. In an accelerator for large emittance beams like muons and unstable nuclei, however, this effect cannot be ignored. Fixed field alternating gradient accelerators overview, status f. Non scaling fixed field alternating gradient ffag accelerators have an unprecedented potential for muon acceleration, as well as for medical purposes based on carbon and proton hadron therapy. Technological advances have made possible the recent construction of several proton ffags, and a wide variety of designs is being studied for diverse applications with electrons, muons. Normalconducting scaling fixed field alternating gradient accelerator for proton therapy j. Both techniques are applied in fixedfield alternatinggradient accelerators ffags, which were intensively studied in the 1950s and 60s with electron models. The creation of strong focusing from the gradients and edges of these magnets. Pulsed spallation neutron source with an induction linac. The design is considered both analytically and via computer modeling.
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