A new accelerator for advanced research and cancer therapy Ken Peach John Adams Institute for Accelerator Science University of Oxford and Royal Holloway University of London Princeton 11 th October 2007

Ken PeachJohn Adams Institute11 x 072 Outline Introduction (Accelerators & Particle Physics) The Neutrino Factory (Why? The Muon Acceleration Challenge) The ns-FFAG Accelerator (non-scaling Fixed-Field Alternating Gradient) EMMA Charged Particle Therapy (CPT) (proton and light-ion cancer treatment) PAMELA Summary

Ken PeachJohn Adams Institute11 x 073 Introduction There are more than 17,000 particle accelerators (> a few MeV) worldwide –Most are used in medicine Linacs, cyclotrons, some synchrotrons… –Next most common in industry Ion implantation etc –Synchrotron Radiation Sources Mostly synchrotrons, coming soon - linacs –Neutron and radionuclide sources Linacs, cyclotrons, synchrotrons, something weird and –For particle physics! A few big synchrotrons (& colliders) –Often with Linacs at the front end And coming soon (maybe) the ILC

Ken PeachJohn Adams Institute11 x 074 Classical Accelerator Types TypeMagnetic Field RFRadius BetatronVariable  Fixed CyclotronFixed Variable SynchrotronVariable Fixed FFAGFixed ~Fixed Linear acccelerators (Linacs)   + assorted others – electrostatic, RFQs etc … + new ideas (laser-plasma for example) …

Ken PeachJohn Adams Institute11 x 075 The Bleeding Edge? Medical accelerators –Mainly linacs and cyclotrons Research accelerators –Mainly synchrotrons Particle Physics applications –Better synchrotrons (LHC) –Better linacs (ILC) Why do we need anything new? –Because life presents new challenges!

Ken PeachJohn Adams Institute11 x 076 HiggsBosonHiggsBoson? Force Carriers Z Z boson W W boson  photon g gluon Generations of matter Generations of matter   -neutrino  tau b bottom t top III   -neutrino  muon s strange c charm II e e-neutrino e electron d down up uI Leptons Quarks Particles and Forces Each with its own ‘antiparticle’ © Brian Foster

Ken PeachJohn Adams Institute11 x 077 The Standard Model The Parameters 6 quark masses –m u, m c, m t –m d, m s, m b 3 lepton masses –m e, m , m  2 vector boson masses –M w, M Z (m , m g =0) 1 Higgs mass –M h 3 coupling constants –G F, ,  s 3 quark mixing angles –  12,  23,  13 1 quark phase – 

Neutrino Factory The “ultimate” neutrino facility

Ken PeachJohn Adams Institute11 x 079 The Standard Model The Parameters 6 quark masses –m u, m c, m t –m d, m s, m b 3 lepton masses –m e, m , m  2 vector boson masses –M w, M Z (m , m g =0) 1 Higgs mass –M h 3 coupling constants –G F, ,  s 3 quark mixing angles –  12,  23,  13 1 quark phase –  Neutrino sector Neutrino masses identically 0!!!!

Ken PeachJohn Adams Institute11 x 0710 Neutrino Mixing Parameters of neutrino oscillation 1 absolute mass scale 2 squared mass diffs 3 mixing angles 1 phase 2 Majorana phases solarAtmospheric Majorana 3G c ij =cos  ij s ij =sin  ij 22

Ken PeachJohn Adams Institute11 x 0711 a =2  2 G F n e E =  E Where is the electron density ;  is the density (g/cm 3 ) ; E is the neutrino energy (GeV ) Why is it hard to measure the parameters? (Richter: hep-ph/ ) c ij =cos  ij, s ij =sin  ij

Ken PeachJohn Adams Institute11 x 0712 What to Measure? Neutrinos e disappearance e   appearance e   appearance  disappearance   e appearance    appearance … and the corresponding antineutrino interactions Note: the beam requirements for these experiments are: high intensityknown flux known spectrum known composition (preferably no background)

Ken PeachJohn Adams Institute11 x 0713 CP-violation FNAL Feasibality Study 1

Ken PeachJohn Adams Institute11 x 0714 A Neutrino Factory is … … an accelerator complex designed to produce >10 20 muon decays per year directed at a detector thousands of km away Muon Acceleration … need to accelerate muons very quickly GeV,   ~0.1msec]

Ken PeachJohn Adams Institute11 x 0715 Neutrino Factory cost drivers High Power proton drivers –MW power, ns pulses RLA or FFAG? –Which is cheaper? RF –30% of the cost? Cooling –How much? (20% of the cost?) BNL Feasibality Study 2

The non-scaling FFAG Accelerator Fixed-Field Alternating Gradient

Ken PeachJohn Adams Institute11 x 0717 Fixed Field Alternating Gradient accelerators Fixed-Field (like a cyclotron) –Rapid acceleration possible –Rapid cycling possible Alternating Gradient (like a synchrotron) –Focussing!!!! Small (er) magnets/beam pipe/vacuum system … and large acceptance The best of both worlds! –So why is the world not full of FFAGs? TypeMagnetic FieldRFRadius FFAGFixed ~Fixed

Ken PeachJohn Adams Institute11 x 0718 Early FFAGs ( ) MURA built several electron FFAGs in the 1950s 20 to 400 keV machine ChandrasekharBohr Radial sector Spiral sector Large complicated magnets c.f. Cyclotron – large simple magnets c.f. Synchrotron – small simple magnets

Ken PeachJohn Adams Institute11 x 0719 Newer FFAG’s (post-2000) The Japanese have built two “proof of principle” proton FFAGs 500 keV proton KEK150 MeV proton KEK

Ken PeachJohn Adams Institute11 x 0720 … but … Why? LARGE COMPLICATED … the magnets are LARGE and COMPLICATED Why does k have to be so large? 1.Larger k means stronger focussing 2. k > 0 means horizontal focussing –This means that the average field increases with radius 3.The momentum compaction   1/(k+1) –Large momentum bite  small orbit excursion Orbit excursion ~ 0.9m + where k >> 1

Ken PeachJohn Adams Institute11 x 0721 Scaling and non-scaling FFAGs where k >> 1 where k = 1 Linear Linear magnets! i.e. quadrupoles Invented in 1999

Ken PeachJohn Adams Institute11 x 0722 Simpler Magnets LARGE COMPLICATED … the magnets are LARGE and COMPLICATED SMALLSIMPLE … to something SMALL and SIMPLE r B (r)

Ken PeachJohn Adams Institute11 x 0723 The ns-FFAG Should combine the advantages of FFAGs –Fixed Field Fast cycling (limited essentially by RF) Simpler, cheaper power supplies No eddy-currents High intensity (pulsed, ~continuous) Low beam losses Easier maintenance and operation Lower stresses –Strong Focussing Magnetic ring Variable energy extraction Higher energies (than cyclotrons) Different ion species possible with relative ease of construction

Ken PeachJohn Adams Institute11 x 0724 … so … where is the catch? Variable tune! Tune ~    c Must cross resonances

Ken PeachJohn Adams Institute11 x 0725 Beam Acceleration coherentResonance is a coherent effect –Can fast acceleration circumvent the resonances? If the momentum changes by a large amount during a single turns, is it possible to leap-frog over the resonance? –Small variation of the path length with momentum (small momentum compaction) Fixed radio-frequency cavities? 10MeV 20MeV |df/f|~0.1% 0.1ns Plots for EMMA

Ken PeachJohn Adams Institute11 x 0726 Does it work? We do not know! –There is no “no-go” theorem Need for a “proof of principle” demonstrator –EMMA Electron Model for Many Applications –Originally Electron Model for Muon Acceleration Funding obtained in the UK to design and build a EMMA – the world’s first non-scaling FFAG accelerator!

Ken PeachJohn Adams Institute11 x 0727 Objectives of the CONFORM Project 1.Show the non-Scaling Fixed-Field Alternating Gradient Accelerators work Build an Electron Model (EMMA) Design a prototype Charged Particle Therapy machine based on ns-FFAGs Protons and carbon ions 2.Develop applications of ns-FFAGs

Ken PeachJohn Adams Institute11 x 0728 EMMA Parameters 42 identical straight length mm Long drift mm F Quad mm Short drift mm D Quad mm

Ken PeachJohn Adams Institute11 x 0729 Location of EMMA Daresbury

Ken PeachJohn Adams Institute11 x 0730 EMMA at the After Neil Bliss ERLP Parameters

Ken PeachJohn Adams Institute11 x 0731 EMMA: Lattice & Magnets B0B0 xx Magnet linear slide After Neil Bliss

Ken PeachJohn Adams Institute11 x 0732 Diagnostics, injection & extraction After Rob Edgecock

Ken PeachJohn Adams Institute11 x 0733 Status of EMMA Funded! (~$10M) –Started 1 st April 2007 Lattice- fixed Component design- ongoing –Prototype quads being measured now Final design- complete Jan 08 Construction- complete Jul 09 Beam studies- until Sep 10 –At least … After Tkeichiro Yokoi

Ken PeachJohn Adams Institute11 x 0734 CONFORM

PAMELA Charged Particle Therapy (CPT) BASROC & CONFORM

Ken PeachJohn Adams Institute11 x 0736 Incidence of Cancer in the UK 13.5% probability, all types (except skin cancer) –Around half are associated with specific risks –Statistically, some will be close to sensitive tissue and difficult to treat surgically or chemically Source: Cancer Research UK

Ken PeachJohn Adams Institute11 x 0737 Why use protons? After Bleddyn Jones X-Rays Protons

Ken PeachJohn Adams Institute11 x 0738 Why use Carbon? Daniela Schulz-Ertner, Heiddelberg

An important statistic “ Radiotherapy remains a mainstay in the treatment of cancer. Comparison of the contribution towards cure by the major cancer treatment modalities shows that of those cured, 49% are cured by surgery, 40% by radiotherapy and 11% by chemotherapy”. RCR document BFCO(03)3, (2003). Chemotherapy provides by far the smallest contribution towards cancer cure yet is much more expensive than radiotherapy and generates a disproportionately large research and media interest. Roger Dale, Hammersmith Hospital and Imperial College

What is RBE? RBE = Relative Biological Effectiveness. A measure of the biological “potency” of a particular type of radiation relative to that of a reference radiation. Reference radiation (conventional x-rays) has RBE = 1 For a given biological end-point: Proton RBEs: ~ 1.1 Neutron RBEs: Carbon ion RBEs: Roger Dale, Hammersmith Hospital and Imperial College

The concept and definition of RBE are both straightforward. Unfortunately…. Even for a particular type of radiation, RBE is not fixed. Its value depends on: a) The size of the dose used at each treatment b) The chosen biological end-point c) The nature of the irradiated tissue Roger Dale, Hammersmith Hospital and Imperial College

Ken PeachJohn Adams Institute11 x 0742 CPT facilities operating & planned

Ken PeachJohn Adams Institute11 x 0743 Hadron Therapy in Chiba (Japan) Borrowed from Rob Edgecock

Ken PeachJohn Adams Institute11 x 0744 Cancer of the Kidney Stage I: TIa N0 M0 80GyE / 16fr. /4wks 治療前 1 year 2 years 3 years 4 years

Ken PeachJohn Adams Institute11 x 0745 Prostate Cancer Results

Ken PeachJohn Adams Institute11 x 0746 We can do better

Monitoring and Control :Key issues for medical applications time Integrated current Synchrotron & cyclotron time Integrated current FFAG Dose uniformity should be < ~2%  To achieve the uniformity, precise intensity modulation is a must Beam of FFAG is quantized.  Active intensity control at the injection level and precise loss control are indispensable. New approach to medical accelerator control is required in PAMELA (New postdoc is employed for the issue) SOBP is formed by superposing Bragg peak Gate width controls dose Step size controls dose intensity modulation Takeichiro Yokoi

Ken PeachJohn Adams Institute11 x 0748 … much better

Ken PeachJohn Adams Institute11 x 0749 The requirements There are obvious potential benefits from proton/light ion therapy –Need to maximise the benefits Requirements –Rapid variable energy extraction –Rapid variable transverse spot scanning –Variable ion species –Accurate dose measurements Flux control

Ken PeachJohn Adams Institute11 x 0750 Synchrotron Cyclotron FFAG Intensity (>100nA) LowPlenty Plenty 1-16nA >100nA MaintenanceNormal HardNormal Extraction eff Good Poor Good OperationNot easy Easy Easy Ions Yes No Yes Variable energy Yes No Yes Multi-extractionPossible No Yes After Y.Mori KEK/Kyoto Advantages of FFAG in Charged Particle Therapy

Ken PeachJohn Adams Institute11 x 0751 Ns-FFAG machine

Ken PeachJohn Adams Institute11 x 0752 PAMELA Preliminary ideas –Cyclotron ~20 MeV (or 8 MeV – 2 ring) –1 or 2 ns-FFAG proton rings 20 MeV  250 MeV (1 ring) 8 MeV  31 MeV & 31 MeV  250 MeV (2 ring) –+ 1 Ion ring 69 MeV/u  450 MeV/u –(proton ring equivalent to 69 MeV/u Carbon)

Ken PeachJohn Adams Institute11 x 0753 Injection and Extraction Small beam excursion of NS-FFAG makes energy variable beam extraction easier  Unique feature for fixed field accelerator However, large tune change requires phase adjustment mechanism in injection & extraction  multi-kicker system QD QF Kicker#2 Kicker#1 Septum ∆p/p=+0.0 Circulating Septum boundary By changing the field strength and direction, beam position in phase space can be adjusted Example of beam extraction (PAMELA)

Ken PeachJohn Adams Institute11 x 0754 Superconducting FFAG Gantries Fixed field of 3.7T Transports MeV/u Length ~15m D Trbojevic/BNL

Ken PeachJohn Adams Institute11 x 0755 BASROC

Ken PeachJohn Adams Institute11 x 0756 Summary Non-scaling FFAG accelerators are: –New –Untried –Interesting for Neutrino physics Cancer therapy –And other applications »Spallation neutron sources, muon sources »Accelerator driven reactors, nuclear waste disposal We will know in ~3 years if they work –Let us hope that they do … they could be very useful devices …