1. High-Power Proton Drivers Alessandro G. Ruggiero Brookhaven National Laboratory FFAG 03 KEK International Center Japan, July 7 - 11, 2003

2. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero2 There are several Applications that require High-Power Proton Drivers Nuclear Physics Facilities Spallation Neutron Sources Production of Tritium Nuclear Waste Transmutation Energy Production Long-Baseline Neutrino Oscillation Neutrino Factories Muon Colliders …

3. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero3 Accelerator Technology Rapid Cycling Accelerators Accumulator Rings Cyclotrons Fixed-Field Alternating Gradient Linear Accelerators (Room Temp.) Linear Accelerators (SuperCond.) Induction Linear Accelerators

4. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero4 Nuclear Physics Facilities EHF, AHF, JHF, TRIUMPF II, … RT Linac 1.2 GeV 30-GeV Main Ring Targets 9-GeV Booster Stretcher Ring Typically 20-50 GeV High-Rep Rate 5-30Hz Intensity ~ 10 13 protons/pulse Average Power ~ 1-5 MW AC Efficiency ~ few % (30-50 MW AC Power) Cyclotron Continuous Beam

5. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero5 AGS now and Upgrade AGS present AGS upgrade SNS Kin. Energy, GeV28 1.0 Protons 10 14 / Cycle0.670.891.04 Rep. Rate, Hz1/32.560 Ave. Power, MW0.101.0

6. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero6 Spallation Neutron Sources Modes of Operation Short Pulse1 - 2 µs Long Pulse1 - 10 ms Continuous Source Requirements Around 1 GeV energy range 1 - 20 MW > 10 15 neutrons/ cm 2 / s

7. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero7 Existing Facilities LAMPF / LANSCE RT Linac 800 MeV60 Hz / 10 ms1 MW PSR Accumulator RingSP80 KW ISIS RCS 800 MeVSP160 kW ANL - IPNS RCS 500 MeVSP10 kW PSI Cyclotron 600 MeVCW600 kW

8. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero8 Layouts LANL-PSR ISIS PSI 70-MeV RTL 800-MeV RCS Target 800-MeV RTL Target Accumulator 600-MeV Cyclotron Target

9. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero9 Oak Ridge SNS 1.3-GeV SCL injecting in Accumulator Ring Hg -Target Short Pulse Mode1.5 µs Average Power1.3 MW Repetition Rate60 Hz Design Requirement:Uncontrolled Losses < 10 –4 (< 1 W/m) 1-ms Pulse Duration SCL Linac RT Linac Accumulator

10. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero10 SuperConducting Linacs (Pulsed)

11. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero11 Proposed Neutron Sources ESS BNL-PSNS 1.3-GeV SCL Double Ion Source Compressor Ring Targets 2 x 2.5 MW @ 50 Hz 600-MeV RTL 30-Hz RCS Targets 2 x 2.5 MW @ 60 Hz 3.6-GeV RCS 100 mA H –

12. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero12 Accelerator-based Continuous Neutron Source

13. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero13 Cyclotrons Dee Deflector Trajectories get densier at Extraction Step given by Energy Gain RF Source Energy & Power Limitation to avoid Activation

14. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero14 Fixed-Field Alternating Gradient Accelerator Constant Field Sector Magnets Large Aperture (~ 1m) Edge Focusing Injection from low-energy Linac Multiturn-Injection (H – ) Space Charge (losses) Adiabatic Capture & Acceleration Motion spirals outward Parking and Stacking Orbit Extraction with Septum/Kicker B1 B2

15. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero15 Induction Linac No RF Sequence of High Power Transformers Moving DC Current (Field) Pulse Large Transverse Aperture (60 cm) Short Beam Pulse (< 1 µs) High beam Pulse Current (> 100 A) High Repetition Rate Low Accelerating Gradient (< 1 MV/m) Switches

16. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero16 Induction Linac - FFAG Induction Linac FFAG Accelerator Positive Ion Source High-Intensity Short Pulse Positive Ions One-Turn Injection (No Foil Stripping) No Accumulation No Stacking Reduced Concern of Uncontrolled Activation A.G. Ruggiero, G. Bauer, A. Faltens, R. Kustom, S.A. Martin, P. Meads, E. Zaplatin, K. Ziegler ICANS-XIII, Villigen PSI, Switzerland

17. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero17 Induction Linac – FFAG Injector Parameters Ave. Beam Power5 MW Rep. Rate200 Hz Final Energy1 GeV3 GeV Ave. beam Current1.25 mA0.42 mA Positive-Ion Source Pulse Length2 µs Duty Cycle0.04 % Peak Current12. 5 A4.2 A Norm. Emittance30 π mm mrad10 π mm mrad Induction Linac Final Energy260 MeV600 MeV Final Pulse Length0.15 µs0.1 µs Init. Acc. Gradient36 kV/m Final Acc. Gradient1 MV/m Total Length380 m720 m Int. Core Diameter60 cm

18. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero18 Induction Linac – FFAG FFAG Accelerator Parameters Final Energy1 GeV3 GeV Injection Energy260 MeV600 MeV Circumference200 m Packing Factor40 % Bending Radius12.74 m Bending Field1.95 - 4.44 kG3.19 - 10.01 kG Momentum Aperture ±  40 % ± 50 % Max. Dispersion2.0 m Max  Function 20 m Magnet Aperture1.6 m2.0 m Magnet Gap30 cm20 cm Space-Charge  0.3 Norm. Emittance400 π mm mrad220 π mm mrad Acceleration Period5 ms Harmonic Number11 RF Frequency0.93 - 1.31 MHz1.19 - 1.46 MHz RF Peak Voltage400 kV600 kV

19. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero19 Multi-Cavity Proton Cyclotron Accelerator Changbiao Wang, V.P. Yakovlev, J.L. Hirshfield, PAC’03, Portland (OR) Stage12345678 RF, MHz1201121049688807264 Radius, cm9298106110120132144172 Length, m206223239281307338392389  E, MeV 63.692.980.996.1124.3135.3177.0182.7 952.7 MeV 1 MeV I-peak = 0.915 A I-ave = 0.122 A Beam Radius = 0.9 mm Pulse Period = 125 ns Duration = 16.7 ns Energy Spread = 1.2 keV TE 111 Solenoid Field = 8.1 T

20. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero20 Accelerator for Production of Tritium (and Nuclear Waste Transmutation) RT Linac 700-MHz, 4-Cells, Doublet-Focusing SCL 100 MeV 260 MeV 1000 MeV  = 0.43  = 0.62  = 0.88 908 m  = 0.48  = 0.71 50 cm Target Tungsten / SS 100 MW CW Proton Power 3/16 Tritium Production Goal (1995) AC Efficiency 40% (250 MW AC-Power) Thermal energy deposition has a limit (~10kW/cm 2 ) Shock thermal waves absent in CW mode

21. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero21 Energy Production SCL are most AC efficient (~ 40%) Magnets require AC Power (10-20%) Large demand of AC Power of 10’s to 100’s MW AC Power Limitation (Reactors?) Need of Energy recovery Scheme Electrons can be decelerated, but Protons are depleted on Targets

22. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero22 Energy Amplifier Target is a granular mixture of inertial material (W or Pb) and of fissionable material (232 Th). Neutrons are initially produced by Spallation of the inertial material. Each spallation neutron initiates a chain reaction with the fissionable material, so that more neutrons are produced. Sub-critical Reactor k = 0.98

23. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero23 Long-Baseline Neutrino Oscillation Neutrino Factories Muon Collider proton X  e ± µ±µ± π±π± µ e ππ LBNOCERN-GSNL Fermilab BNL Japan NFCERN ISIS US Collaboration µCInternational Collaboration

24. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero24 CERN - Gran Sasso 500 kW

25. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero25 BNL  Homestake Super Neutrino Beam (28 GeV, 1 MW) Fermilab (0.5 - 2 MW, 40 GeV primary proton beam) 2540 km Homestake BNL

26. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero26 8-GeV Fermilab SCL (1) SNS Front-End @ 402.5 MHz (2) DTL @ 402.5 MHz up to 87 MeV (3) 805-MHz SNS type SCL in three sections (  = 0.47, 0.61, 0.81) (4) 1.2 GHz “TESLA” cryomodules from 1.2 to 8 GeV (  = 1) (1) (2) (3) (4) Main Injector Active Length671 m Repetition Rate10 Hz Beam Current25 mA Pulse Length1 ms Beam Intensity1.5 x 10 14 protons / pulse Linac Beam Power, Ave.2 MW Peak200 MW 8 GeV

27. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero27 Collaboration Proposal of - Factory

28. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero28 Alternative Scheme for Neutrino Factory a 15-GeV Proton Driver (PD), a π - µ Production Channel ( πµ PC), that is a solid target immediately followed by a transport channel made of a super-conducting 20-T solenoid magnet where the π mesons decay and the µ mesons are produced, an accelerating section consisting of a 2-GeV SCL with two re-circulating SCLs ( µ SCL) for the acceleration of the µ mesons to 32 GeV, and a 32-GeV muon Storage Ring ( µ SR), where the µ mesons circulate until they decay in neutrinos. No Ionization Cooling required Proton Driver µ SC Linac & Re-circulators π-µ Production Channel µ Storage Ring Beam

29. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero29 15-GeV Proton Driver for -Factory PD Injector 2 GeV 3, 6, 9, 12, 15 GeV PD Re-circulator (4-passes) 4, 7, 10, 13 GeV 5, 8, 11, 14 GeV Target 1 GeVSC Sector Linacs

30. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero30 Muon Acceleration 32-GeV Re-circulator 12-GeV Re- circulator To µSR 2-GeV SCL

31. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero31 One FFAG Period Packing Factor  /R=70 % B (average)=1.0 Tesla FODO cells phase advance = 90 o  E / turn=5 MeV Bunch Area=2 π eV-µs Momentum Spread=± 2 x 10 –3 Norm. Emittance (full)=1 π mm mrad

32. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero32 0.2 - 1.2 GeV FFAG FFAGInjection12345 EnergyMeV20040060080010001200  0.56620.71310.79240.84810.87500.8986 MomentumGeV/c0.64440.95431.21901.46331.69601.9214 Magn. RigidityT-m2.14963.18304.06604.88095.65736.4091  m2.14963.18304.06604.88095.65736.4091 Circumferencem19.2928.5736.5043.8150.7857.53  m--1.03340.88300.81490.77630.7518 No. Periods--812162024 Period Lengthm--2.41182.38092.28102.19062.1158 Sector Lengthm--1.6881.6671.5971.5331.481 Driftm--0.7240.7140.6840.6570.635  - max m--8.238.137.797.487.22  - max m--5.133.372.431.861.50 f - revolutionMHz8.8037.4876.5145.7645.1704.686 a (full)mm3.462.832.452.192.001.85  (full) mm10.266.754.853.733.002.50 a +  mm13.729.587.305.925.004.35  E E mm70.2724.8012.557.565.053.61

33. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero33 Cascade of FFAG 200 400 6008001,200 MeV

34. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero34 Applications AGS-SCLPSNSACNSEAAPT/NWT Ave. Power50 kW5 MW10 MW 100 MW Rep. Rate2.5 Hz60 HzCW Pulse Length 0.7 ms1.3 ms-- Inj. Energy200 MeV100 MeV200 MeV 100 MeV End Energy1.2 GeV1.3 GeV1.25 GeV1.2 GeV Ave. Curr.40 µA4 mA8 mA 80 mA Peak Curr.30 mA100 mA8 mA 80 ma  0.0250.0830.0067 0.067

35. July 7-11, 2003 FFAG 03 Alessandro G. Ruggiero35 Varying Field B For the same constrain  < 100 cm B = 1 TeslaNo. of FFAG’s = 4 2 2 4 1