Development of NS-FFAG EMMA & PAMELA
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Transcript of Development of NS-FFAG EMMA & PAMELA
Development of NS-FFAG EMMA & PAMELA
Takeichiro Yokoi
Introduction ...• FFAG(Fixed Field Alternating Gradient) Accelerator has an ability
of rapid particle acceleration with large beam acceptance. wide varieties of applications
Particle physics -factory, muon source, proton driver
-factory-factory
FFAGMedical
Particle therapy, BNCT, X-ray source
Particle Particle therapytherapy
FFAG
Energy ADSR, Nucl. Transmutation
ADSRADSRFFAG
CONFORM CONFORM ((Construction of a Non-scaling FFAG for Oncology, Research and Medicine) aims to develop the Non-scaling FFAG as a versatile accelerator. (Project HP: www.conform.ac.uk)
EMMA
PAMELA
(PAMELA)
Scaling FFAG & Non-Scaling FFAGBoth have large acceptance and ability of fast acceleration * Acceleration speed of fixed field accelerator is unlimited (in synchrotron, ramping speed of magnet limits the repetition rate)
Scaling FFAG Similar orbit shape Large beam excursion Stable betatron tune Combined function(Brk)
Non-Scaling FFAG Non-similar orbit shape Small beam excursion (small path length variation) Large tune change Linear lattice (quadrupole etc)
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Already Constructed
PoP FFAG(KEK)
It has never been built
EMMA
CONFORM : Construction of a Non-scaling FFAG for Oncology, Research and Medicine
EMMA ( PM: R.Edgecock ) Rutherford Appleton Lab Daresbury Lab. Cockcroft Ins.
Manchester univ. John Adams Ins. BNL (US) FNAL (US) CERN LPNS (FR) TRIUMF (CA)
PAMELA (PM: K.Peach) Rutherford Appleton Lab Daresbury Lab. Cockcroft Ins.
Manchester univ. Oxford univ. John Adams Ins. Imperial college London Brunel univ. Gray Cancer Ins. Birmingham univ. FNAL (US) LPNS (FR) TRIUMF (CA)
JAI team (alphabetical)
J. Cobb, K. Peach, S. Sheehy, H. Witte T. Yokoi, (G.Morgan)
Two main projects are going on ….. (1) EMMAEMMA: Construction of electron machine (prototype for muon accelerator)
(2) PAMELAPAMELA : Design study of NS-FFAG particle therapy facility ( Proton & Carbon )
EMMA: Electron Model for Many Applications
Electron NS-FFAG as a proof of principle is to be built as 3-year project.(host lab: Daresbury lab.)
It is a scaled-down model of muon accelerator for neutrino factory. Research items are . . . (1) Research of beam dynamics of NS-FFAG (2) Demonstration of NS-FFAG as a practical accelerator (3) Demonstration of fast acceleration with fixed frequency RF
3mm(normalized)Acceptance
1.3GHzRF
10~20MeV(variable)Extraction energy
10~20MeV(variable)Injection energy
16.57mCircumference
42 (doublet Q) Number of Cell
5m5m
Muon Acceleration
EMMA development in Oxford
(1) Magnet design
(2) Tracking in 3D field
(3) Injection & Extraction
Vertical tune
Baseline model
Tracking
PAMELA : Particle Accelerator for MEdicaL Applications
Advantage of particle therapy : good dose concentration and better biological effectiveness Advantage of FFAG : (1) Higher intensity (compared to ordinary synchrotron ) (2) Flexible machine operation ( compared to cyclotron ) (3) Simultaneous(multi-port) beam extraction
Standard Photons
Standard Protons
photonphoton protonproton
PAMELA : design study of particle therapy facility for proton and carbon using NS-FFAG ( prototype or slow accelerating NS-FFAG Many applications!!! Ex. ADSR )
Spot scanning
PAMELA : Medical requirement Simultaneous energy and intensity modulation is a requirement for flat dose distribution in spot scanning
Intensity modulation of 1/100 is required to achieve the dose uniformity of 2%.
1kHz repetition can scan more than 100 voxel/sec 1 kHz repetition is a present goal (impossible for synchrotron)Medical requirements are now getting clear
By G. Morgan
PAMELA : Beam Dynamics
Field imperfection severely affects beam blow up in the resonance
crossing
rf: 5kv/celldx: 100µm(RMS)
dx: 10µm(RMS)
dx: 1µm(RMS)
Beam blow up rate can be estimated quantitatively Design Criteria for proton NS-FFAG is now in hand !!
Integer resonance
Half integer resonance
Challenges: Understanding the Challenges: Understanding the
dynamics in resonance crossingdynamics in resonance crossing
~2m
PAMELA : Lattice
Integer resonance crossing must be circumvented. Tune-stabilization by introducing higher order multipole field is required
One feasible option : Non-Linear NS-FFAG (simplified scaling FFAG) : B=B0 (R/R0)k B=B0 [1+k∆R/R0+k(k-1)/2 (∆R /R0 )
2 ····] * Eliminating higher order multipole
By S. Sheehy
(1) Long straight section (~2m)
(2) Small tune drift ( <1)
(3) Limited multipole (Up to decapole)
Beam dynamics is being investigated
Doable lattice option is now in hand !!
Challenges: Tune stabilized NS-FFAG latticeChallenges: Tune stabilized NS-FFAG lattice
PAMELA : Magnet
by H.Witte
Superposition of helical field can form multipole field
Dipole Quadrupole
DecapoleOctapole
Sectapole
Applicable to superconducting magnet Well-controlled field quality Present lattice parameters are within engineering limit
~17cm
40cm
Feasible option for magnet
Challenges: Large aperture, short length, strong fieldChallenges: Large aperture, short length, strong field
PAMELA : Beam Acceleration
time
Energy
1ms
Option 1
1mstime
Energy Option 2
Option 1: P Nrep2
Option 2: P Nrep
Multi-bunch acceleration is preferable from the viewpoint of efficiency and upgradeability
PRISM RF (Osaka univ)
Experiment using PRISM cavity is planned in this October
Beam acceleration experiment using real FFAG is also planned.
PRISM rf (Osaka univ. , Japan) has similar specifications to PAMELA
Challenges : Fast enough, but more efficient !Challenges : Fast enough, but more efficient !
1ms(PV2)
PAMELA : Beam Extraction
Resonance point
H
v
In scaling FFAG, vertical tune can be varied by changing relative field strength of bending magnets
Beam blow-up in half integer resonance can be used for resonant extraction
Fast extraction & energy variable slow extraction in fixed field accelerator !! (Ideal for practical application ex. ADS , Real Alternative of existing medium energy synchrotron )
Lattice is under investigation
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Challenges: High intensity, Flexibility, and reliabilityChallenges: High intensity, Flexibility, and reliability
PAMELA Parameter specification : Almost fixed Baseline design : by 2009 Refining design, Funding : 2010
R&Ds : Prototype helical magnet, Prototype RF cavity Multi-bunch acceleration Resources : 1 FTE engineer
EMMA Lattice : fixed Component designs : ongoing Measurement of test magnet : on going Design : to be completed by Jan 08 Construction : to be completed by Jul 09
+ 1Year of beam study
EMMA Lattice : fixed Component designs : fixed Measurement of test magnet : on-going Design : fixed (production : on-going) Construction : to be completed by Jul 09
+ 1Year of beam study
Status & Schedules ...
PAMELA Parameter specification : Almost fixed Baseline design : by 2009 Refining design, Funding : 2010
R&Ds : Prototype helical magnet, Prototype RF cavity Multi-bunch acceleration Prototype Ring Resources : 1 FTE engineer