130 likes | 267 Views
Summary: FFAG WORKSHOP nonscaling electron model muon FFAGs. C. Johnstone Fermilab. Electron Model. Advanced understanding and full lattice designs Linear field lattices: Berg, Koscielniak, Johnstone, Keil, Trbojevic Isochronous lattices: G. Rees
E N D
Summary: FFAG WORKSHOP nonscaling electron modelmuon FFAGs C. Johnstone Fermilab
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
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
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
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
Electron Model Magnet Dipole plus quad field lines
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
Electron Model Diagnostics • OTR foils + cameras: • Transverse phase space profiles • Bunch train 109/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
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.
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
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 !!!
International Collaborative Projects • Role and contributions to PRISM? • Proton FFAGs? • Define working groups? • Range of applications – medical group • SBIR applications? Reactor FFAGs