FFAGs for medical applications

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Status of EMMA
Rob Edgecock for the EMMA Collaboration
BNL, CERN, CI, FNAL, JAI, LPSC Grenoble, STFC,
TRIUMF
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Outline

• Introduction
• EMMA parameters
• Status
• Hardware
• Magnets
• RF
• Diagnostics
• Conclusions

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Introduction
Large acceptance and CW acceleration for
muons Now also studied for hadron therapy, ADSR,
proton drivers But unique optical features No
such machine ever built Work so far entirely
theoretical Codes not benchmarked Must build
one EMMA
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EMMA Parameters

• Electron model of muon FFAGs parameters
  scaled muon ? electron
• (Very important RD project for NF)
• Parameters - 10 to 20 MeV - Doublet
  lattice - 42 cells - total length
  394.481mm - long drift 210.000mm
  - F 58.782mm -
  short drift 50.000mm - D
  75.699mm - RF 1.3GHz, 1 cavity every
  other cell - 8 lattice configurations -
  bunch charge 16-32pC - precise measurement
  of beam parameters

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Aims

• Demonstrate that non-scaling optics work
• Study resonances in detail - emittance
  growth vs acceleration rate -
  vs tune variation -
  vs parabola shape - effect of
  errors - detailed probe using injector
• Study longitudinal dynamics in detail -
  transmission vs parameter values - emittance
  growth vs parameter values - tof behaviour
  effect of non-parabolic nature - effect of
  moving parabola - effect of errors
• Check effect of transverse dynamics
• Compare with predictions
• ..

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Status

• Funding started on 1st April 2007
• Injector built and being commissioned
• EMMA design essentially complete
• EMMA hardware see later!
• Main milestones Major components on
  site 1st Aug 08 Construction complete 23rd
  Jul 09 Start experimental programme 18th Sep
  09 EMMA phase 1 complete 9th Jul 10

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Injector

• Need a flexible injector - injection at
  any energy - small emittance -
  sufficient intensity in a single
  bunch Energy Recovery Linac Prototype at
  DL

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EMMA Design
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Magnets
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Ring Magnets

• Should be combined function
• Implemented as quadrupoles, mounted on slides

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Ring Magnets
Prototypes built by Tesla F is OK, D being
improved Order for 84 magnets also won by
Tesla Delivery in 6 months
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Septum
Nominal angle 72o In practice 90o
Initially impossible! After F?D flip 2
solutions Best awaits tracking Stray field
not too high
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Magnet PSUs
Up to 42 F existing SRS DC power converter Up
to 42 D
8 magnets powered individually introduce
errors non-uniformity Septums existing SRS
pulsed power convert. Kickers
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RF Cavity Design
Requirements
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RF Cavity Design
Prototype cavity ordered from Niowave (Cu)
Delivery early March Power coupler from Times
Microwave
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RF Power
Cascaded power distribution
LLRF DimTel Inc assessing adapting existing
board (SNS LLRF) to EMMA
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RF Power
Power sources IOTs e2v or CPI
PSU re-use SRS PSU (large mods
required) be-spoke (small, new, low cost)
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Diagnostics
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Diagnostics
BPMs 4 82 3 89 ? need to be cheap!
Two options for readout electronics analogue
being developed in UK digital being developed
at FNAL Comparison and selection spring 08
Purpose built 4-button BPMs Simulations suggest
required precision for 25pC
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Diagnostics
BPM locations
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Diagnostics
Screens 7 2 6 15
Purpose built Probably YAG due to
charge Otherwise OTR with gated CCD cameras
(expensive!)
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Diagnostics
Wires 0 2 0 2
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Diagnostics
WCM 1 1 1 3 being developed at
FNAL lots of experience! Faraday cups 1 0
1 2 same as on ERLP Beam loss monitors 0
4 0 4 same as on ERLP Spectrometer magnet
0 0 1 1 re-use from SRS
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Conclusions

• EMMA will - prove the principle of
  NS-FFAGs - demonstrate their use for NF
• Funded as part of the CONFORM project
• EMMA collaboration - works well -
  always constructive
• Machine design is essentially complete
• Most hardware is well advanced
• Still on schedule
• First operation August 2009