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High-Power Proton Drivers. Alessandro G. Ruggiero Brookhaven National Laboratory FFAG 03 KEK International Center Japan, July 7 - 11, 2003. There are several Applications that require High-Power Proton Drivers. Nuclear Physics Facilities Spallation Neutron Sources
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High-Power Proton Drivers Alessandro G. Ruggiero Brookhaven National Laboratory FFAG 03 KEK International Center Japan, July 7 - 11, 2003
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 • … Alessandro G. Ruggiero
Accelerator Technology • Rapid Cycling Accelerators • Accumulator Rings • Cyclotrons • Fixed-Field Alternating Gradient • Linear Accelerators (Room Temp.) • Linear Accelerators (SuperCond.) • Induction Linear Accelerators Alessandro G. Ruggiero
Nuclear Physics FacilitiesEHF, AHF, JHF, TRIUMPF II, … RT Linac 1.2 GeV 30-GeV Main Ring Targets Continuous Beam 9-GeV Booster Cyclotron Stretcher Ring Typically 20-50 GeV High-Rep Rate 5-30Hz Intensity ~ 1013 protons/pulse Average Power ~ 1-5 MW AC Efficiency ~ few % (30-50 MW AC Power) Alessandro G. Ruggiero
AGS now and Upgrade Alessandro G. Ruggiero
Spallation Neutron Sources • Modes of Operation • Short Pulse 1 - 2 µs • Long Pulse 1 - 10 ms • Continuous Source • Requirements • Around 1 GeV energy range • 1 - 20 MW • > 1015 neutrons/ cm2 / s Alessandro G. Ruggiero
Existing Facilities • LAMPF / LANSCE • RT Linac 800 MeV 60 Hz / 10 ms 1 MW • PSR • Accumulator Ring SP 80 KW • ISIS • RCS 800 MeV SP 160 kW • ANL - IPNS • RCS 500 MeV SP 10 kW • PSI • Cyclotron 600 MeV CW 600 kW Alessandro G. Ruggiero
Accumulator Target 800-MeV RTL 70-MeV RTL Target 800-MeV RCS Layouts • LANL-PSR • ISIS • PSI 600-MeV Cyclotron Target Alessandro G. Ruggiero
Oak Ridge SNS 1.3-GeV SCL injecting in Accumulator Ring Hg -Target Short Pulse Mode 1.5 µs Average Power 1.3 MW Repetition Rate 60 Hz Design Requirement: Uncontrolled Losses < 10–4 (< 1 W/m) 1-ms Pulse Duration Accumulator RT Linac SCL Linac Alessandro G. Ruggiero
SuperConducting Linacs (Pulsed) Alessandro G. Ruggiero
Proposed Neutron Sources • ESS • BNL-PSNS 2 x 2.5 MW @ 50 Hz 1.3-GeV SCL Targets Double Ion Source Compressor Ring 3.6-GeV RCS 2 x 2.5 MW @ 60 Hz 100 mA H– Targets 600-MeV RTL 30-Hz RCS Alessandro G. Ruggiero
Accelerator-based Continuous Neutron Source Alessandro G. Ruggiero
Dee Cyclotrons Deflector Step given by Energy Gain RF Source Trajectories get densier at Extraction Energy & Power Limitation to avoid Activation Alessandro G. Ruggiero
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 Alessandro G. Ruggiero
Switches 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) Alessandro G. Ruggiero
Induction Linac Positive Ion Source FFAG Accelerator Induction Linac - FFAG A.G. Ruggiero, G. Bauer, A. Faltens, R. Kustom, S.A. Martin, P. Meads, E. Zaplatin, K. Ziegler ICANS-XIII, Villigen PSI, Switzerland • High-Intensity Short Pulse • Positive Ions • One-Turn Injection (No Foil Stripping) • No Accumulation • No Stacking • Reduced Concern of Uncontrolled Activation Alessandro G. Ruggiero
Induction Linac – FFAG Injector Parameters Alessandro G. Ruggiero
Induction Linac – FFAG FFAG Accelerator Parameters Alessandro G. Ruggiero
Multi-Cavity Proton Cyclotron AcceleratorChangbiao Wang, V.P. Yakovlev, J.L. Hirshfield, PAC’03, Portland (OR) 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 952.7 MeV 1 MeV TE111 Solenoid Field = 8.1 T Alessandro G. Ruggiero
Accelerator for Production of Tritium(and Nuclear Waste Transmutation) RT Linac 700-MHz, 4-Cells, Doublet-Focusing SCL Target Tungsten / SS b = 0.48 b = 0.71 100 MeV 260 MeV 1000 MeV b = 0.43 b = 0.62 b = 0.88 908 m 100 MW CW Proton Power 3/16 Tritium Production Goal (1995) AC Efficiency 40% (250 MW AC-Power) 50 cm Thermal energy deposition has a limit (~10kW/cm2) Shock thermal waves absent in CW mode 50 cm Alessandro G. Ruggiero
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 Alessandro G. Ruggiero
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 Alessandro G. Ruggiero
µ± µe π± protonXe± π Long-Baseline Neutrino OscillationNeutrino FactoriesMuon Collider LBNO CERN-GSNL Fermilab BNL Japan NF CERN ISIS US Collaboration µC International Collaboration Alessandro G. Ruggiero
CERN - Gran Sasso 500 kW Alessandro G. Ruggiero
BNL Homestake 2540 km BNL Homestake Super Neutrino Beam (28 GeV, 1 MW)Fermilab(0.5 - 2 MW, 40 GeV primary proton beam) Alessandro G. Ruggiero
8-GeV Fermilab SCL 8 GeV (1) (2) (3) (4) Main Injector (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 (b = 0.47, 0.61, 0.81) (4) 1.2 GHz “TESLA” cryomodules from 1.2 to 8 GeV (b = 1) Active Length 671 m Repetition Rate 10 Hz Beam Current 25 mA Pulse Length 1 ms Beam Intensity 1.5 x 1014 protons / pulse Linac Beam Power, Ave. 2 MW Peak 200 MW Alessandro G. Ruggiero
Collaboration Proposal of n - Factory Alessandro G. Ruggiero
Alternative Scheme for Neutrino Factory π-µ Production Channel µ Storage Ring • a 15-GeV Proton Driver (PD), • a π - µ Production Channel (πµPC), that is a solid target immediately followed by a transport channel made of a super-conducting 20-T solenoid magnet where theπ mesons decay and the µ mesons are produced, • an accelerating section consisting of a 2-GeV SCL with two re-circulating SCLs (µSCL) for the acceleration of the µ mesons to 32 GeV, and • a 32-GeV muon Storage Ring (µSR), where the µ mesons circulate until they decay in neutrinos. • No Ionization Cooling required Beam Proton Driverµ SC Linac & Re-circulators Alessandro G. Ruggiero
P D I nj ec to r 2 G e V 3, 6, 9, 12, 15 G e V T a r g et P D 5, 8, 11, 14 G e V R e- c irc ul at or ( 4 - p a ss e s ) 1 G e V S C S e c t o r L in ac s 4, 7, 10, 13 G e V 15-GeV Proton Driver for n-Factory Alessandro G. Ruggiero
32-GeV Re-circulator To µSR 2-GeV SCL 12-GeV Re-circulator Muon Acceleration Alessandro G. Ruggiero
One FFAG Period Packing Factor r/R = 70 % B (average) = 1.0 Tesla FODO cells phase advance = 90o DE / turn = 5 MeV Bunch Area = 2 π eV-µs Momentum Spread = ± 2 x 10–3 Norm. Emittance (full) = 1 π mm mrad Alessandro G. Ruggiero
Applications Alessandro G. Ruggiero
FFAG (CW) 200 MeV 2.2 GeV Next Stage Injector Rep. Rate, Intensity, Pulse Length Alessandro G. Ruggiero
qF 2D p2, r2, B2 qD p1, r1 , B1 FFAG Sector Geometric Design B = B0 ( r / r0 )n p0 = B0 r0 B1,2 = B0 ( r1,2 / r0 )n p1,2 = B1,2 r1,2 r1,2 = r0 (1 ± D / r0) p1,2 = p0 (1 ± D / r0) n + 1 R = (p2 / p1) 1/(n+1) G = (R + 1) / (R – 1) r0 = D G N = number of Sectors = 2 (F – D) = 2 π / N Alessandro G. Ruggiero
200 MeV - 2.2 GeV CW FFAG Design 400 turns = ~ 1 msec B0 = 2.76 kG n = 109 (76) D = 10 cm LF / LD = 3 Pack. Fact. = 0.8 / period = 0.25 N = 31 E = 5 MeV / turn e, norm, full = 1 π mm mrad DFD lattice with thin-lens calculation to derive , , Alessandro G. Ruggiero
FFAG ASBurner 1.2-1.5 GeV SCL AGS Upgrade RT Linac: 200 MeV 1 π mm mrad 2 π eV-µs ± 0.2 % 30 mA 2.5 Hz (5 Hz) 0.7 m (2.4 ms) Booster : 1.5 GeV 201 m 50 π mm mrad 7.5 Hz 3 x (5 x 1012) ASBurner 40 GeV 810 m 2.5 Hz (5 Hz) 0.9 x 1014 p/p 1.43 MW (2.86 MW) AGS: (24) 28 GeV 804 m 2.5 Hz (5 Hz) 0.9 x 1014 p/p 1.0 MW (2.0 MW) FFAG 2.2 GeV 210 m CW 2.7 kG 3.2 x 1014 p/AGS pulse 10.2 MW Alessandro G. Ruggiero
FFAG RF Proton Drivers Layouts Target No Stacking Beam Makers SCL Stacking Accumulator Compressor AGS RCS MI RF Alessandro G. Ruggiero
Sector Gradient Magnets: B = B0 (r/r0)n p2 B2 B0 ….. careful!! …. p0 = B0 r0 ≠ pcentral r0 p1 B1 pcentral = B0 R0 Dp / DR R2 R1 Important Condition to be satisfied q1 = q2 that is L1 / R1 = L2 / R2 DL / DR = q Calculate --> DL / Dp = qDp / DR Careful again !! Dp / DR ≠ Dp / Dr But p = B(R) R Dp /DR = B(R) + R D B(R) / DR etc…. q1 q2 Machine Centre Alessandro G. Ruggiero
Isochronous Condition L = LF + LD + D T = L / c = constant dT / dp = 0 dL / dp – (L / ) d / dp = 0 d / dp = c / E03 dL / dp = cL / 3 E0 L/L0 = x [ (1 + 02 02) / (1 + 02 02 x2)] x = p / p0 Bending Condition (LF – LD) / R = q = constant R dLF / dp – R dLD / dp = = (LF – LD) dR / dp Alessandro G. Ruggiero