Thesis
Scaling fixed field accelerators: theory and modelling of horizontal- and vertical-excursion accelerators
- Abstract:
-
Fixed Field Accelerators, or FFAs, are accelerators that use time-independent magnetic fields, permitting the orbit to move as the beam is accelerated. Spatially-dependent magnetic fields allow for the control of orbit geometry during acceleration and the control of focussing strength along the orbit. Scaling FFAs represent the subset of fixed field accelerators in which the magnetic fields follow scaling laws that ensure geometric similarity between closed orbits of different energies and energy-independent focussing behaviour. Vertical-excursion FFAs (vFFAs) present a novel variant on the scaling FFA template where higher-energy orbits are vertically translated copies of lower energy ones, introducing complexities in optics and orbits due to coupled particle motion across the two transverse planes and non-planar orbit behaviour. Because of this, previous design and study of vFFA rings has depended entirely on numerical integration methods.
This study presents analytical methods for studying optics in both horizontal- and vertical-excursion FFAs, deriving for the first time an analytic model of the vFFA. A multipole decomposition approach, termed ‘harmonic analysis,’ is developed to study vFFA optics in cases where the analytic model has limitations. This technique is then further used in the study of nonlinear (higher-order) effects in conventional FFAs beyond the capabilities of the linear analytic modelling. The nonlinear effects studies are additionally benchmarked with experimental studies of amplitude-dependent tune shift, showing good agreement. To demonstrate the strength of the newly-developed analytic techniques, the vFFA as a muon accelerator stage for a muon collider is studied, where insights provided by the analytic model enable an optimisation that was not previously possible.
Actions
Access Document
- Files:
-
-
(Preview, Dissemination version, pdf, 28.1MB, Terms of use)
-
Authors
Contributors
- Institution:
- Rutherford Appleton Laboratory
- Role:
- Supervisor
- Institution:
- Rutherford Appleton Laboratory
- Role:
- Supervisor
- ORCID:
- 0000-0003-1432-0518
- Institution:
- University of Oxford
- Division:
- MPLS
- Department:
- Physics
- Sub department:
- Particle Physics
- Role:
- Supervisor
- ORCID:
- 0000-0002-7653-7205
- Institution:
- University of Oxford
- Division:
- MPLS
- Department:
- Physics
- Sub department:
- Particle Physics
- Role:
- Supervisor
- ORCID:
- 0000-0001-5699-3046
- Institution:
- University of Oxford
- Division:
- MPLS
- Department:
- Physics
- Sub department:
- Particle Physics
- Role:
- Examiner
- ORCID:
- 0000-0002-7224-8334
- Funder identifier:
- https://ror.org/057g20z61
- DOI:
- Type of award:
- DPhil
- Level of award:
- Doctoral
- Awarding institution:
- University of Oxford
- Language:
-
English
- Keywords:
- Subjects:
- Deposit date:
-
2025-03-25
- ARK identifier:
Terms of use
- Copyright holder:
- Max Emil Topp-Mugglestone
- Copyright date:
- 2024
If you are the owner of this record, you can report an update to it here: Report update to this record