Muon Acceleration Plan

David KelliherASTeC/STFC/RAL

UKNF WP1, October 9th, 2008

Remit of Muon Acceleration study• Study includes current RLA and FFAG stages

(possibly including the 50 GeV upgrade)

Lattice possibilitesFFAG

• Doublet, Triplet and FODO non-scaling lattices under consideration

• One or two cavities per cell

RLA• Dogbone • (or Racetrack with FFAG arcs)

FFAG lattice study – Step 1• Current possible lattices must firstly be

compared in terms of feasibility of injection/extraction (e.g. strength of required kicker/septum)

• From this consideration a couple of candidate lattices may emerge. It is also possible that a modified lattice will have to be designed to enable injection/extraction (e.g. lattice with longer straight section).

FFAG lattice study – Step 2• The candidate lattices that emerge from step 1 will be subject

to detailed tracking studies.• Study of longitudinal dynamics will 1. Calculate the required voltage to avoid longitudinal blow-up.2. Assess the feasibility of serpentine acceleration in the

presence of cavity phase and voltage errors.• In transverse dynamics the problems associated with tune

excursion will be studied. 1. Investigate affect of any chromaticity correction on dynamic

aperture.2. The dynamic aperture in the presence of misalignments and

gradient errors to be calculated. 3. Consider methods of orbit correction

RLA lattice study – Step 1• Understand present design by Alex Bogacz.• Investigate whether improvements can be

made to the focusing optics and to the switchyard design

• Study a new arc utilising the FFAG concept.

RLA lattice study – Step 2• Detailed tracking study in the baseline lattice

that results from step 1. In particular,1.Solve time of flight problem. This may require

the addition of non-linear multipole terms.2.Calculate the resulting reduction in dynamic

aperture.

Beam transport lines• Design of the transport lines between

accelerating stages and the storage rings will be included in the study

Milestones• Complete Step 1, i.e. decide on candidate lattices. We

estimate that this will take 1 year.• Step 2 – detailed evaluation of the candidate lattices +

design of beam transport lines. This step will take more time if a previously unstudied lattice is chosen from step 1 and will take in the region 1-2 years.

Personal Contribution (Step 1)• Begin by working on injection and extraction in the non-

scaling FFAG1. By tracking the injection orbit, calculate kicker and septum

strength required to keep beam envelope within magnet aperture for each of the lattices under consideration.

2. If necessary, study affect of adding longer straight sections into a non-scaling FFAG.

• Undertake code development as required (ongoing).1. Investigate how a fringe field can be implemented in Zgoubi

tracking code that is valid for particles far from magnetic axis.2. Contribute to end-to-end simulation effort.

Personal Contribution (Step 2)• Participate in step 2 studies, i.e. studies of

longitudinal and transverse dynamics in candidate lattices and design of transfer lines, using Zgoubi and PTC tracking codes