1. FFAG Workshopfermilab April 2005 f Summary: FFAG WORKSHOP nonscaling electron model muon FFAGs C. Johnstone Fermilab

2. FFAG Workshopfermilab April 2005 f Electron Model  Advanced understanding and full lattice designs  Linear field lattices: Berg, Koscielniak, Johnstone, Keil, Trbojevic  Isochronous lattices: G. Rees  Full simulation, tracking and error analysis  Meot – full simulation tools + fringe field ability  Machida – alignment and field quality analysis  Keil – error studies with MAD

3. FFAG Workshopfermilab April 2005 f Electron Model Technical Specifications  Full ring  Factor of 2 energy gain  Lattice choice: doublet min(cost+phase-slip)  Periodicity: 42 identical cells  Injection  Injector: 8-35 MeV Daresbury Energy Recovery Superconducting Linac (ERSCL)  Injection energy: 8-12 MeV, 130  - 140  /cell  Extraction energy 16-24 MeV, 25  30  /cell

4. FFAG Workshopfermilab April 2005 f Electron Model Goals  POP of nonscaling FFAG accelerator (muon accelerator demonstration – other applications?)  Large momentum compaction-reduced apertures  Multi-resonance crossing without correction  Includes integer and half integer resonances  Bucketless acceleration  1 and 2 fixed points, 5-20 turns  Transverse and longitudinal dynamics  Under phase-slip conditions relative to rf  Chromatic dependence of beta functions through acceleration cycle  Symmetric and asymmetric parabolic pathlengths

5. FFAG Workshopfermilab April 2005 f Electron Model Magnet Specifications  Preliminary magnet design: permanent magnet + trim coils (slot constraints)  For 10 MeV injection  Permanent dipole component of 1.5 kG  Permanent quad component of ~4T/m  Quad trim coil provides +/- 20%  Variation in dipole component can be provided by varying injection energy or side plate location  Slot length: 10-12 cm  PM/core length: 5-7cm  Magnet spacing: 5-7 cm

6. FFAG Workshopfermilab April 2005 f  Electron Model Magnet Dipole plus quad field lines

7. FFAG Workshopfermilab April 2005 f Electron Model Magnet Tolerances  Good-field region: 5-20 turns  1% gradient error at +/-5cm  Thermally stable PM material  8 cm allows injection/extraction? – no special magnets in ring  1Hz operation or less  No cooling  No eddy current problems

8. FFAG Workshopfermilab April 2005 f Electron Model Diagnostics  OTR foils + cameras:  Transverse phase space profiles  Bunch train 10 9 /bunch  Single bunch operation – checking  Longitudinal distribution – streak camera  Resistive wall monitor – verify beampipe size and cut-off frequencies  1.3 GHz BPMs  Single and multi-bunch design  Fit inside magnets  ~20 micron resolution

9. FFAG Workshopfermilab April 2005 f Fermilab Main Injector bpm

10. FFAG Workshopfermilab April 2005 f Electron Model RF specifications  1.3 GHz to match Daresbury Linac  Frequency variation to change fixed points  21-25 cm straight required for installation  About half of the 42 cells will have rf.

11. FFAG Workshopfermilab April 2005 f What can we afford under a NEST  ¼ of the ring or 10 cells (~0.5 million Euros with 30% contingency)  Requires design and engineering contributions on part of participating institutions.  Fermilab will propose funding design and possibly a prototype magnet to lab management  Control system/operation – Daresbury  Others  Hardware contributions:  Streak and CCD cameras, OTR assemblies…  Inventory institutions

12. FFAG Workshopfermilab April 2005 f What would a nonscaling arc demonstrate  Achieve high momentum compaction and nonscaling optics  Verify nonscaling lattice over the factor of two change in energy—before building full ring!  Prototype and get diagnostics operational  Multi-bunch – single bunch operation  Intensity dependence and other systematics  Optics  Beam-based alignment  Beam-based field measurements  Check variation of optics and orbits using variable injection energy !!! fringe field characterization !!!

13. FFAG Workshopfermilab April 2005 f International Collaborative Projects  Role and contributions to PRISM?  Proton FFAGs?  Define working groups?  Range of applications – medical group  SBIR applications? Reactor FFAGs