Scaling FFAG Research Articles

Serpentine acceleration in zero-chromatic FFAG accelerators

A fixed rf frequency acceleration scheme is required for rapid-acceleration and producing high-intensity beam in non-relativistic energy region. For these requirements, new-type of fixed rf frequency acceleration scheme called serpentine acceleration is applied in scaling FFAG. To examine a longitudinal motion with serpentine acceleration, longitudinal hamiltonian in scaling FFAG with fixed rf frequency is derived analytically. Then details of serpentine acceleration scheme in scaling FFAG are presented. To demonstrate serpentine acceleration in scaling FFAG, beam experiment has been done with electron scaling FFAG ring. Results are analyzed and confirm the serpentine acceleration in scaling FFAG. Finally, longitudinal design for ADS proton driver with this scheme is presented.

ADVANCEMENT OF THE SCALING FFAG ACCELERATOR FOR ADSR, PULSED-SNS AND MUON ACCELERATION

Progress in the study of beam optics and acceleration of the scaling FFAG accelerator has been presented in this paper.

HARMONIC NUMBER JUMP ACCELERATION OF MUON BEAMS IN SCALING FFAG RINGS

The harmonic number jump acceleration in scaling FFAG rings is considered in this paper. Constraints fixed by the acceleration scheme on the lattice design are detailed. An example of a 3.6 to 12.6 GeV muon lattice which satisfy these constraints is presented.

Non-Linear Field Generated by a Distribution of Conductors in a Spiral FFAG

FAGs accelerators re-appeared fifteen years ago to be of interest for new accelerator projects. These synchrotrons allow fast acceleration because of the fixed field magnets. To compensate the beam trajectory radius increase, the radial magnetic gradient follows a non-linear law B0 (r/R0)k. In the frame of the RACCAM (Recherche en Accelerateur et Application Medicales) project in France, a scaling spiral FFAG ring is developed for medical applications. Magnets have spiral edges to make beam focusing. Here is described the dipole design study with flat horizontal poles which allow a low variation of the vertical tune. This study presents how to produce B0 (r/R0)k with distributed polar conductors.

Spiral FFAG lattice design tools. Application to 6-D tracking in a proton-therapy class lattice

Methods have been developed, based on ray-tracing, for 3-D modelling of magnetic fields and particle motion in spiral scaling FFAG accelerators. They allow efficient simulation of particle motion in the presence of the strong field non-linearities found in FFAG magnets, and of overlapping fields in configurations of neighbouring magnets. This provides a useful tool for spiral FFAG lattice design and optimization, and for 6-D tracking studies. As illustration, the approach is applied to the design of a 180MeV medical class proton FFAG now being studied under the RACCAM hadron-therapy project.

Numerical methods for 6-D dynamics simulations in FFAG rings

A geometrical method for 3-D modeling of the magnetic field in scaling and non-scaling FFAG magnets, installed in a stepwise ray-tracing code, is presented. It is applied for illustration to 6-D multiturn tracking in a 150 MeV radial sector proton FFAG.

Developments in the ray-tracing code Zgoubi for 6-D multiturn tracking in FFAG rings

A geometrical method for 3-D modeling of the magnetic field in scaling and non-scaling FFAG magnets has been installed in the ray-tracing code Zgoubi. The method in particular allows a good simulation of transverse non-linearities, of field fall-offs and possible merging fields in configurations of neighboring magnets, while using realistic models of magnetic fields. That yields an efficient tool for FFAG lattice design and optimizations, and for 6-D tracking studies. It is applied for illustration to the simulation of an acceleration cycle in a 150 MeV radial sector proton FFAG.