1. Introduction to NS-FFAGs and EMMA Rob Edgecock STFC Rutherford Appleton Laboratory

2. Outline The FFAG principle Brief history of FFAGs Non-scaling FFAGs Requirements for EMMA EMMA status Work still to be done Conclusions

3. Fixed magnetic fields and AG focussing important! Two types: scaling and non-scaling Start with scaling………. What is an FFAG? Fixed Field Alternating Gradient accelerator Magnetic field

4. What is an FFAG? Fixed magnetic field  cyclotron like Magnetic field variation B(  ) Fixed RF frequency (CW operation) Frequency modulated (pulsed beam) UniformClassicalSynchro- AlternatingSector-focusedFFAG But, strong focussing  synchrotron like Combine cyclotron and synchrotron features for applications In particular, cancer therapy

5. A Brief History of FFAGs Invented in 1950s: Ohkawa in Japan, Symon in US Kolomensky in Russia Interest, then and now, properties arising from FF & AG Fixed Field: - fast cycling, limited (sometimes) only by RF - simpler, inexpensive power supplies - no eddy-current effects, cyclical coil stress - high acceptance - high intensity – pulsed and continuous - low beam loss and activation - easy maintenance - easy operation Strong focussing: - magnetic ring - beam extraction at any energy - higher energies/ions possible

6. A Brief History of FFAGs 1950s/60s: most extensive work at MURA 20 to 400 keV machine Operated at MURA in 1956 Bohr Chandrasekhar

7. A Brief History of FFAGs Spiral sector machine Operated at MURA in 1957 1950s/60s: most extensive work at MURA

8. A Brief History of FFAGs 100keV to 50MeV machine Operated at MURA in 1961 1950s/60s: most extensive work at MURA

9. A Brief History of FFAGs Invented in 1950s: most extensive work at MURA Proton proposals failed: technical complexity/energy Re-invented late 1990’s in Japan for muon acceleration - ideal due to high acceptance & very rapid cycling - for a Neutrino Factory

10. A Brief History of FFAGs Invented in 1950s: most extensive work at MURA Proton proposals failed: technical complexity/energy Re-invented late 1990’s in Japan for muon acceleration - ideal due to high acceptance & very rapid cycling - for a Neutrino Factory - first proton PoP FFAG built, 500 keV, 2000 - 2 nd proton FFAG, 150 MeV, 2003 - prototype for proton therapy

11. Current Projects   ADSR @ Kyoto – funded – being commissioned   BNCT @ Kyoto – funded – under construction   PRISM @ Osaka – funded – under construction   LAPTOP @ Mitsubishi – 6 MeV prototype being built   Spiral FFAG for therapy @ Grenoble – design study

12. But……… Orbit excursion ~ 0.9m + where k=7.5 Magnets are large, complex & expensive! Accelerators larger than ideal

13. Non-Scaling FFAGs Non-Scaling FFAGs Non-scaling FFAGs - throw out “scaling” requirement  much more flexibility Much smaller, simpler and cheaper magnets More compact machines

14. Non-Scaling FFAGs Non-Scaling FFAGs Invented in 1999 Accelerator facility for Particle Physics: - for muon acceleration More recently, potential for other applications noted High intensity proton beams:   fundamental physics   neutron production   muon source   ADSR   etc Proton and ion beams for cancer therapy

15. But……. But……. NS-FFAGs have potential, but……… They also have unique optical features:   small orbit excursion = large momentum compaction   rapid tune changes  multiple resonance crossings   asynchronous acceleration Machines still at early stages & not optimised All work so far is theoretical!   no such machine ever built   may not work, assumptions wrong, h/w impossible, etc Must build one: proof-of-principle NS-FFAG Must also do more complete study for hadron therapy And eventually build a prototype

16. BASROC BASROC British Accelerator Science and Radiation Oncology Consortium Aims: - build proof-of-principle NS-FFAG - EMMA - design carbon & proton therapy FFAGs - design prototype - PAMELA - seek funding to build - study other applications Submitted proposal to 2006 BT round Funded from 1 st April 2007 EMMA already running for ~2 years

17. EMMA EMMA Electron Model of Many Applications 10-20MeV electron NS-FFAG “Purest” type for proof-of-principle Other types basically more complicated technology Will be built at DL in Cheshire use ERLP/ALICE as injector Design is essentially complete Hardware & prototypes being ordered

18. EMMA EMMA

20. EMMA Design EMMA Design Essentially complete Still to be done:   Extraction below 13MeV: - many lattices - large beam acceptance - should be complete a few weeks   ALICE to Faraday (cup) tracking: - check all lattices work - check complete acceptance transmitted - nobody yet doing this

21. EMMA Hardware EMMA Hardware Magnet prototypes built and tested 84 production magnets ordered Staged delivery until August Prototype RF cavity almost complete

22. EMMA Hardware EMMA Hardware Magnet prototypes built and tested 84 production magnets ordered Staged delivery until August Prototype RF cavity almost complete 20 production cavities to be ordered soon PSUs for magnets and RF designed Kicker magnets and septa going for tender soon

23. EMMA Diagnostics EMMA Diagnostics Not as advanced as the other hardware Requirement are defined Solutions have been identified:

24. EMMA Diagnostics EMMA Diagnostics

25. Work required now:   Check specifications are correct   Detector & electronics design   Construction of test devices   Testing   Construction of final devices   Installation   Commissioning Additional effort for all above very welcome

26. EMMA Commissioning EMMA Commissioning Once EMMA is constructed: commissioning! Will be a long process! Will require control system to:   present diagnostics measurements   run simulations to compare Additional effort for control system required Additional effort for commissioning also required!

27. Conclusions EMMA FFAGs could revolutionise accelerator technology Much interest world-wide Recent focus on non-scaling FFAGs EMMA will - prove the principle of NS-FFAGs - demonstrate their use for NF Funded as part of the CONFORM project Machine design is essentially complete Most hardware is well advanced Still on schedule First operation ~ August 2009