High-Power Proton Drivers Alessandro G. Ruggiero Brookhaven National Laboratory FFAG 03 KEK...

High-Power Proton Drivers

Alessandro G. RuggieroBrookhaven National Laboratory

FFAG 03 KEK International Center

Japan, July 7 - 11, 2003

July 7-11, 2003 FFAG 03

Alessandro G. Ruggiero 2

There are several Applications that require High-Power Proton Drivers

Nuclear Physics FacilitiesSpallation Neutron SourcesProduction of TritiumNuclear Waste TransmutationEnergy ProductionLong-Baseline Neutrino OscillationNeutrino FactoriesMuon Colliders…

July 7-11, 2003 FFAG 03


Accelerator Technology

Rapid Cycling Accelerators

Accumulator Rings

Cyclotrons

Fixed-Field Alternating Gradient

Linear Accelerators (Room Temp.)

Linear Accelerators (SuperCond.)

Induction Linear Accelerators

July 7-11, 2003 FFAG 03


Nuclear Physics FacilitiesEHF, 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 ~ 1013 protons/pulse

Average Power ~ 1-5 MW

AC Efficiency ~ few % (30-50 MW AC Power)

Cyclotron

Continuous Beam

July 7-11, 2003 FFAG 03


AGS now and UpgradeAGS

presentAGS

upgradeSNS

Kin. Energy, GeV 28 28 1.0

Protons 1014 / Cycle 0.67 0.89 1.04

Rep. Rate, Hz 1/3 2.5 60

Ave. Power, MW 0.10 1.0 1.0

1.5-GeV Booster

28-GeV AGS200-MeVLinac

1.2-GeVSCL

July 7-11, 2003 FFAG 03


Spallation Neutron Sources

Modes of OperationShort Pulse 1 - 2 µs

Long Pulse 1 - 10 ms

Continuous Source

RequirementsAround 1 GeV energy range

1 - 20 MW

> 1015 neutrons/ cm2 / s

July 7-11, 2003 FFAG 03


Existing Facilities

LAMPF / LANSCERT Linac 800 MeV 60 Hz / 10 ms 1 MW

PSRAccumulator Ring SP 80 KW

ISISRCS 800 MeV SP 160 kW

ANL - IPNSRCS 500 MeV SP 10 kW

PSICyclotron 600 MeV CW 600 kW

July 7-11, 2003 FFAG 03


Layouts

LANL-PSR

ISIS

PSI

70-MeV RTL

800-MeV RCS

Target

800-MeV RTLTarget

Accumulator

600-MeV CyclotronTarget

July 7-11, 2003 FFAG 03


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

SCL Linac

RT Linac

Accumulator

July 7-11, 2003 FFAG 03


SuperConducting Linacs (Pulsed)

Medium Front End Low-Energy Energy High-Energy

RT Linac Section Section Section To the AGS

201.25 MHz 805 MHz 1,610 MHz 1,610 MHz

200 MeV 400 MeV 800 MeV 1.2 GeV

Front End Medium-Beta High-Beta DTL CCL Section Section To the SNS

402.5 MHz 805 MHz 805 MHz 805 MHz

185.6 MeV 387 MeV 1.0 GeV

July 7-11, 2003 FFAG 03


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 Hz3.6-GeV RCS

100 mA H–

July 7-11, 2003 FFAG 03


Accelerator-based Continuous Neutron Source

Layout of Front End

Ion Source RFQ Buncher10 mA 350 MHz 350 MHz

to 200-MeV RT Linac

35 kV 750 keV

Layout of the SCL for the ACNS

Medium Front End Low-Energy Energy High-Energy

RT Linac Section Section Section To the Target

700 MHz 700 MHz 1,400 MHz 1,400 MHz

200 MeV 400 MeV 800 MeV 1.25 GeV

Side View of SCL

Target Area

Klystron Gallery

30-40 ft Cryo-Plant Service Buildings Beam Dump

Linac Tunnel Transport

SNS AGSUpgrade

ACNS

Kinetic Energy, GeV 1.0 1.2 1.25Ave. Power, MW 1.0 0.045 10Duty Factor, % 6.0 0.18 100Repetition Rate, Hz 60 2.5 --Pulse Length, ms 1.0 0.72 --Peak Power, MW 16.7 25 10Ion Source Current, mA 35 35 10Ave. Beam Current, mA 1.0 0.035 8Peak Beam Current, mA 26 21 8Protons / Bunch, x 108 4.3 8.7 1.43RF, MHz 805 805 – 1,610 700 – 1,400Coupler RF Power, MW 170 - 350 260 - 400 80 - 155Length, m 158 120 163Inj. Energy, MeV 185.6 200 200Cryo. Power (2.1oK), kW 0.5 0.15 5.3Ave. AC Power, MW 3.1 0.28 23Ave. Gradient, MV/m 3.1 – 6.5 5.3 – 10.0 3.3 – 8.7Efficiency, % 26 - 30 9 - 16 35 - 40Cost, M$ 110 97 85Operation Cost, M$ / yr 2.0 0.18 15.2

July 7-11, 2003 FFAG 03


Cyclotrons

DeeDee

DeflectorDeflector

Trajectories get densier at Extraction

Step given by Energy Gain

RF Source

Energy & Power Limitation to avoid Activation

July 7-11, 2003 FFAG 03


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

July 7-11, 2003 FFAG 03


Induction LinacNo RFSequence of High Power TransformersMoving DC Current (Field) Pulse

Large Transverse Aperture (60 cm)Short Beam Pulse (< 1 µs)High beam Pulse Current (> 100 A)High Repetition RateLow Accelerating Gradient (< 1 MV/m)

Switches

July 7-11, 2003 FFAG 03


Induction Linac - FFAG

Induction Linac

FFAGAccelerator

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

July 7-11, 2003 FFAG 03


Induction Linac – FFAG Injector Parameters

Ave. Beam Power 5 MW

Rep. Rate 200 Hz

Final Energy 1 GeV 3 GeV

Ave. beam Current 1.25 mA 0.42 mA

Positive-Ion Source

Pulse Length 2 µs

Duty Cycle 0.04 %

Peak Current 12. 5 A 4.2 A

Norm. Emittance 30 π mm mrad 10 π mm mrad

Induction Linac

Final Energy 260 MeV 600 MeV

Final Pulse Length 0.15 µs 0.1 µs

Init. Acc. Gradient 36 kV/m

Final Acc. Gradient 1 MV/m

Total Length 380 m 720 m

Int. Core Diameter 60 cm

July 7-11, 2003 FFAG 03


Induction Linac – FFAG FFAG Accelerator Parameters

Final Energy 1 GeV 3 GeV

Injection Energy 260 MeV 600 MeV

Circumference 200 m 200 m

Packing Factor 40 % 40 %

Bending Radius 12.74 m 12.74 m

Bending Field 1.95 - 4.44 kG 3.19 - 10.01 kG

Momentum Aperture ±40 % ± 50 %

Max. Dispersion 2.0 m 2.0 m

Max Function 20 m 20 m

Magnet Aperture 1.6 m 2.0 m

Magnet Gap 30 cm 20 cm

Space-Charge 0.3 0.3

Norm. Emittance 400 π mm mrad 220 π mm mrad

Acceleration Period 5 ms 5 ms

Harmonic Number 1 1

RF Frequency 0.93 - 1.31 MHz 1.19 - 1.46 MHz

RF Peak Voltage 400 kV 600 kV

July 7-11, 2003 FFAG 03


Multi-Cavity Proton Cyclotron AcceleratorChangbiao Wang, V.P. Yakovlev, J.L. Hirshfield, PAC’03, Portland (OR)

Stage 1 2 3 4 5 6 7 8

RF, MHz 120 112 104 96 88 80 72 64

Radius, cm 92 98 106 110 120 132 144 172

Length, m 206 223 239 281 307 338 392 389

E, MeV 63.6 92.9 80.9 96.1 124.3 135.3 177.0 182.7

952.7 MeV1 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

TE111

Solenoid Field = 8.1 T

July 7-11, 2003 FFAG 03


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

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/cm2)

Shock thermal waves absent in CW mode

July 7-11, 2003 FFAG 03


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 SchemeElectrons can be decelerated, but Protons are depleted on Targets

July 7-11, 2003 FFAG 03


Energy Amplifier

Target

Cooling

Heat - Exchange

Steam Turbines

Electric Power Generator

Ion Source12 mA, CW

402.5 MHzRFQ

805 MHzDTLnormal-conducting

805 MHz SuperConducting Linac

0.1 GeV 0.3 GeV 1.0 GeV

10 mA

Power to drive Linac, 25 MW

External Load 400 MW

Facility, 5 MW

proton

1-3 GeV Source

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

July 7-11, 2003 FFAG 03


Long-Baseline Neutrino OscillationNeutrino FactoriesMuon Collider

proton X e±

µ±

π±

µ e

π

LBNO CERN-GSNL

Fermilab

BNL

Japan

NF CERN

ISIS

US Collaboration

µC International Collaboration

July 7-11, 2003 FFAG 03


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

CERN - Gran Sasso

500 kW

July 7-11, 2003 FFAG 03


BNL Homestake Super Neutrino Beam (28 GeV, 1 MW)

Fermilab (0.5 - 2 MW, 40 GeV primary proton beam)

2540 km

HomestakeBNL

July 7-11, 2003 FFAG 03


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 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

8 GeV

July 7-11, 2003 FFAG 03


Collaboration Proposal of - Factory

July 7-11, 2003 FFAG 03


Alternative Scheme for Neutrino Factory

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 the π 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

Proton Driver µ SC Linac & Re-circulators

π-µ Production Channel µ Storage Ring

Beam

July 7-11, 2003 FFAG 03


15-GeV Proton Driver for -Factory PD Injector 2 GeV 3, 6, 9, 12, 15 GeV

PDRe-circulator

(4-passes)

4, 7, 10, 13 GeV

5, 8, 11, 14 GeVTarget

1 GeV SC Sector LinacsMode of Operation Continuous Wave (CW)Final Kinetic Energy 15 GeVAverage Proton Current 10 mAAverage Proton Power 150 MWSCL-Injector Energy 2 GeVSCL- Injector Frequency 201.25 MHz to 116 MeV

805 MHz to 400 MeV1.61 GHz to 2 GeV

Number of Passes in SCL-Sectors 4 (5 in the first Linac Sector)Energy Gain for each Pass 1 GeVFrequency of SCL-Sectors 1.61 GHzExtracted Beam Emittance 0.3 π mm-mrad (rms, norm.)Extracted Bunch Area 1.0 π MeV-degree at 1.61 GHzrms Momentum Spread < 1 x 10-4

rms Bunch Length < 1 mmBeam Bunching Frequency 201.25 MHz, 1 bunch every 8 rf buckets

at 1.61 GHzBunch Spacing 150 cm

July 7-11, 2003 FFAG 03


Muon Acceleration 32-GeV Re-circulator

12-GeV Re-circulator

To µSR

2-GeV SCL

Mode of Operation Continuous Wave (CW)Final Kinetic Energy 32 GeVAverage Muon Current 2 x 0.14 mAAverage Muon Power 2 x 4.5 MWSCL-Injector Energy 2 GeVSCL- Injector Frequency 201.25 MHz to 800 MeV

805 MHz to 2 GeVEnergy of First Re-Circulator 12 GeVEnergy of Second Re-Circulator 32 GeVNumber of Passes in SCL-Sectors 3 (4 in the first Linac Sector of each

Re-Circulator)Energy Gain for each Pass 1 GeV for 1st Re-Circulator

2 GeV for 2nd Re-CirculatorFrequency of Re-Circulator Linacs 1.61 GHzExtracted Beam Emittance 122 π mm-mrad (full)Extracted Bunch Area 0.024 π eV-sMomentum Spread ±3 x 10-3

Bunch Length ±0.2 nsBeam Bunching Frequency 201.25 MHzBunch Spacing 150 cm

July 7-11, 2003 FFAG 03


One FFAG Period

Packing Factor /R = 70 %

B (average) = 1.0 Tesla

FODO cells phase advance = 90o

E / turn = 5 MeV

Bunch Area = 2 π eV-µs

Momentum Spread = ± 2 x 10–3

Norm. Emittance (full) = 1 π mm mrad

July 7-11, 2003 FFAG 03


Applications

AGS-SCL

PSNS SNS ACNS CERN EAAPT

NWT

Average Power

50 kW 5 MW 1.3 MW 10 MW 20 MW 10 MW 100 MW

Rep. Rate

2.5 Hz 60 Hz 60 Hz CW CW CW CW

Pulse Duration

0.7 ms 1.3 ms 1.0 ms -- -- -- --

InjectionEnergy

200 MeV 100 MeV 187 MeV 200 MeV 200 MeV 200 MeV 100 MeV

Ejection Energy

1.2 GeV 1.3 GeV 1.3 GeV1.25 GeV

2 GeV 1.2 GeV 1.2 GeV

Ave. Current

40 µA 4 mA 1 mA 8 mA 20 mA 8 mA 80 mA

Peak Current

30 mA 100 mA 35 mA 8 mA 20 mA 8 mA 80 mA

(FFAG)

0.025 0.083 0.029 0.0067 0.017 0.0067 0.067

July 7-11, 2003 FFAG 03


FFAG (CW)

200 MeV 2.2 GeVNext Stage

Injector

Rep. Rate,

Intensity,

Pulse Length

July 7-11, 2003 FFAG 03


FFAG Sector Geometric Design

2Dp2, r2, B2

p1, r1 , B1

F

D

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

July 7-11, 2003 FFAG 03


200 MeV - 2.2 GeV CW FFAG Design

FFAG Injection Ejection

Energy MeV 200 2200 (1500)

0.5662 0.9543

Momentum GeV/c 0.6444 2.9947

Magn. Rigidity T-m 2.1496 9.9892

kG 1.678 4.514

r m 12.81 22.13

Period Length m 11.16

Sector Length m 8.93

Drift m 2.23

Circumference m 346.01 (273.27)

- max m 38.11

- max m 6.12

p/p (half) % 0.2 0.02

a (full) mm 7.45 3.46

(full) mm 12.25 1.22

a + mm 19.70 4.68

E mm 83.92 10.71

400 turns = ~ 1 msec

B0 = 2.76 kGn = 109 (76)D = 10 cmLF / LD = 3Pack. Fact. = 0.8 / period = 0.25N = 31E = 5 MeV / turnnorm, full = 1 π mm mrad

DFD lattice with thin-lens calculation to derive , ,

July 7-11, 2003 FFAG 03


AGS UpgradeRT Linac: 200 MeV

1 π mm mrad2 π eV-µs± 0.2 %30 mA2.5 Hz (5 Hz)0.7 m (2.4 ms)

Booster : 1.5 GeV201 m50 π mm mrad7.5 Hz3 x (5 x 1012)

AGS: (24) 28 GeV 804 m2.5 Hz (5 Hz)0.9 x 1014 p/p

1.0 MW (2.0 MW)

ASBurner 40 GeV810 m

2.5 Hz (5 Hz)0.9 x 1014 p/p

1.43 MW (2.86 MW)

FFAG 2.2 GeV 210 m CW 2.7 kG

3.2 x 1014 p/AGS pulse 10.2 MW

Booster AGS

Multi-Turn H– Inject.

RTLinac

A

B Multi-Turn H– Inject.

ASBurner

1.2-1.5 GeV SCL

FFAG

July 7-11, 2003 FFAG 03


Proton Drivers Layouts

Beam Makers SCL

Target

No Stacking

Accumulator

Compressor

AGS

RCS

MI

Stacking

FFAG

RFRF

July 7-11, 2003 FFAG 03


Sector Gradient Magnets: B = B0 (r/r0)n

R2 R1

p1 B1 pcentral = B0 R0

p2 B2

r0

B0 ….. careful !! …. p0 = B0 r0 ≠ pcentral

Machine Centre

Important Condition to be satisfied

1 = 2 that is L1 / R1 = L2 / R2

L / R =

Calculate --> L / p = p / R

Careful again !! p / R ≠ p / r

But p = B(R) R

p /R = B(R) + R B(R) / R etc….

1

2

p / R

July 7-11, 2003 FFAG 03


Isochronous Condition

LF LD D p2

L2

p0

p1 L0

L1

200 MeV 1.1 GeV 2.2 GeV

L/L0 = x [ (1 + 02 0

2) / (1 + 02 0

2 x2)]

x = p / p0

L = LF + LD + D T = L / c = constant

dT / dp = 0 dL / dp – (L / ) d / dp = 0

d / dp = c / E0 3 dL / dp = cL / 3 E0

Bending Condition

(LF – LD) / R = = constant

R dLF / dp – R dLD / dp =

= (LF – LD) dR / dp

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High-Power Proton Drivers Alessandro G. Ruggiero Brookhaven National Laboratory FFAG 03 KEK...

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