, IC LondonJ. Pasternak Fast circular accelerators for future muon and proton beams J. Pasternak, Imperial College / RAL STFC

, IC LondonJ. Pasternak Fast circular accelerators for future muon and proton beams Outline of the talk 1.Introduction. 2.Present day high intensity proton accelerators. 3.FFAG accelerators and their history. 4.FFAG projects around the world.. 5.Neutrino Factory and muon acceleration. 6.Summary.

, IC LondonJ. Pasternak Kaon physics B physics Muon physics Neutrino beams Neutrino Factory Muon Collider Neutron sources ADS for energy production … LHC, ILC, CLIC, Muon Collider, laser acceleration… Introduction - HEP road map Cosmic rays Radio and visible telescopes CMB …

, IC LondonJ. Pasternak ISIS70 MeV H – linac 0.2 MW MeV H + synchrotron J-PARC180 MeV H – linac 0.2 MW GeV + 50 GeV synchrotrons LANSCE800 MeV H + /H – linac 0.8 MW + accumulator ring PSI590 MeV cyclotron1.2 MW + 72 MeV injector cyclotron SNS1 GeV H – linac 0.6 MW 2 + accumulator ring 1: For limited time during commissioning; ultimate design 1 MW with 400 MeV linac. 2: Still commissioning; 1 MW design operation. Present day high intensity drivers

, IC LondonJ. Pasternak ISIS Facility at RAL 70 MeV H – linac 800 MeV proton synchrotron TS-1

, IC LondonJ. Pasternak ISIS Injection MICE pion line

, IC LondonJ. Pasternak ISIS MW Upgrade The reference solution is based on 3.2 GeV 50 Hz RCS (Rapid Cycling Synchrotron) with bucket-to-bucket transfer from the present 800 MeV ISIS ring. The design can be further upgraded with the help of direct charge exchange injection from 800 MeV H - linac

, IC LondonJ. Pasternak Introduction FFAG – Fixed Field Alternating Gradient accelerator is a ring with a strong focusing lattice, very large momentum acceptance and small dispersion First proposed by Okhawa and Symon et al. In 1953 Electron model from 50ties (MURA) POP-world first proton FFAG (Mori et al )

, IC LondonJ. Pasternak Advantages of FFAG accelerators: Constant fields allow for very high repetition rate (100 Hz – kHz) Constant tunes (or linear fields) give large acceptances Strong focusing reduces dispersion (orbit excursion), which limits the magnet size High Intensity FFAG applications: High power proton drivers (4-10 MW) for neutrino factory, muon collider, neutron sources, ADS… Acceleration of unstable particle beams (muons, radioactive ions) Medical applications

, IC LondonJ. Pasternak FFAG with respect to other circular machines Machine Cyclotron Synchrotron FFAG Magnetic field constant changing constant RF frequency constant changing changing (not always) Orbit changing constant changing Tune changing constant constant (not always)

, IC LondonJ. Pasternak Scaling versus Non-Scaling FFAG FFAG type Scaling Non-scaling Magnetic field linear Orbits scale non-scale Dispersion small very small

, IC LondonJ. Pasternak FFAG type Scaling Non-scaling Tune constant changing (not always) Acceleration RF with swing RF with swing stationary bucket quasi-isochronous harmonic number jump – HNJ HNJ y x

, IC LondonJ. Pasternak History of FFAG Okhawa i Symon et al. MURA two beam accelerator MURA spiral ring

, IC LondonJ. Pasternak History (2) 2000 First proton FFAG with RF acceleration, group of prof. Y. Mori at KEK – POP (Proof Of Principle) machine MeV ring 2008 Beam extracted from the KURRI chain

, IC LondonJ. Pasternak Current Projects and R&D KURRI FFAG chain for ADS studies PRISM – phase rotation for muons ERIT – neutron source for BNCT EMMA – first non-scaling ring RACCAM – R&D for hadrontherapy PAMELA – R&D for hadrontherapy (subject of another HEP seminar soon) IDS – R&D towards the Neutrino Factory

, IC LondonJ. Pasternak KURRI ADS chain Projects (1)

, IC LondonJ. Pasternak PROJECTS (3) (Phase Rotated Intense Slow Muon source)

, IC LondonJ. Pasternak PROJECTS (2) EMMA (Electron Model for Many Applications) EMMA – first non-scaling FFAG: Model for muon accelerator at the Neutrino Factory Demonstration of novel acceleration principle (10 –20 MeV) Experiments for fast resonance crossing Under construction in DL (UK).

, IC LondonJ. Pasternak Motivations for a Medical FFAG Hadrontherapy shows up to be more effective for cancer treatment comparing to the conventional radiotherapy! Advantages of FFAG for medical applications: - High dose delivery 5 Gy/min/l (high rep rate – 100 Hz) - Variable energy operation without enegy degraders - Compact size and low cost - Simple and efficient extraction - Stable and easy operation - Multiple extraction ports - Bunch to Pixel treatment.

, IC LondonJ. Pasternak Medical FFAG - RACCAM Project Variable energy from injector by changing the stripper position –(H - AIMA cyclotron) + Variable magnetic field in FFAG magnets = Variable extraction energy from FFAG for treatment

, IC LondonJ. Pasternak RACCAM Project (2) Number of cells 10 Field index 5. Spiral angle 53.7° R max 3.46 m R min 2.8 m (Qx, Qy) (2.77, 1.64) B max 1.7 T p f 0.34 Injection energy 6-15 MeV Extraction energy MeV h 1 RF frequency 1.9 – 7.5 MHz Bunch intensity 3  10 9 protons Normal conducting magnets Magnet prototype successfully constructed at SigmaPhi!

, IC LondonJ. Pasternak Muon acceleration for Neutrino Factory and Muon Collider may be realized in FFAG accelerators operating with constant RF frequency Japan NuFact project American NuFact project Current R&D for Neutrino Factory

, IC LondonJ. Pasternak NuFact – Lab for leptonic CP violation search

, IC LondonJ. Pasternak Reference IDS Neutrino Factory Design nsFFAG

, IC LondonJ. Pasternak IDS designs by J. Scott Berg

, IC LondonJ. Pasternak Scott’s FODO, 1 out of 62 cells lqd lqf dxd thd/2 (angle) b0d, b1d D,+dxf b0f, b1f thf/2 (angle) F,- n = 62 lqd = e+00 m thd = e-01rad dxd = e-02 m b0d = e+00 T b1d = e+01 T/m lqf = m thf = e-02 rad dxf = e-03 m b0f = e-01 T b1f = e+01 T/m Ldrift = 2 m

, IC LondonJ. Pasternak Qx, Qy E, MeV Beam dynamics in IDS nsFFAG E, MeV T, ns Orbit in D magnet, m E, MeV x’, rad x, m

, IC LondonJ. Pasternak Problems of IDS nsFFAG Very compact lattice with short straight sections - very difficult injection/extraction. Due to natural chromaticity time of flight depends on amplitude – longitudinal blow-up and acceptance limitation. Beam loading. Natural chromaticity Corrected chromaticity, study by S. Machida

, IC LondonJ. Pasternak Horizontal extraction m m Parameters: 10 kickers – 1.4 m, T and septum – 1.4 m, 4 T.

, IC LondonJ. Pasternak Vertical extraction m m Parameters: 6 kickers – 1.4 m, 0.07 T and septum – 1.4 m, 4 T.

, IC LondonJ. Pasternak Summary and future plans for IDS nsFFAG Work continues on injectio/extraction, towards lattices with insertions and chromaticity correction Further beam dynamics studies are needed. We need a study of hardware components, magnets, RF, kickers, septum, etc. Reference design for the muon acceleration in the Neutrino Factory exists. Beam dynamics has been successfully checked using independent codes. Extraction looks not impossible, but very challanging!

, IC LondonJ. Pasternak Summary: We are observing a rebirth of FFAGs after 50 years of silence. Machines constructed until now work very well! Several projects are under implementation. FFAGs will have a bright future in physics (high intensity drivers, muon accelerators, etc.) FFAG might become a next generation medical accelerator of choice