Fermilab Proton Driver Project

Weiren Chou for Bill FosterFermilab, U.S.A.

October 20, 2004

Presentation at the Proton Driver SessionICFA-HB2004, Bensheim, Germany, Oct 18-22, 2004

Chou for Foster ICFA-HB2004 Workshop, October 20, 2004 2

Introduction

Neutrino Superbeam/Proton Driver is one of 28 new facilities on the DOE’s 20-year strategic plan.

Fermilab Long Range Planning Committee has recommended the proton driver as one of two candidates for a future construction project at Fermilab. (LC is the other one.)

Early this year Fermilab director issued a charge to Bill Foster and Steve Geer to prepare a CD0 document for establishing mission needs for a proton driver.

There were two options considered: 8 GeV RCS or 8 GeV sc rf linac. The ICFA decision to choose sc rf technology for a future ILC gave a big

boost to the linac option. Fermilab director recent announced to go for the linac option. R&D for LC and proton driver will go in parallel. The core part of this R&D is to establish a Superconducting rf Module

Test Facility (SMTF) at Fermilab. This will be a multi-institution collaboration project. A LOI is being circulated. A number of instituion have signed up.

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Introduction (cont…)

The Proton Driver project is defined as:

“a complete replacement of our current 400 MeV linac and 8 GeV Booster, accompanied by Main Injector upgrades.”

Beam power spec: 8 GeV Proton Driver: 0.5 MW

8–120 GeV upgraded Main Injector: 2 MW

Total beam power: 2.5 MW

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Proton Driver Study II (Fermilab-TM-2169)

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8 GeV Linac Parameters

Energy GeV 8

Particle Type H, e

Rep. Rate Hz 10

Active Length m 671

Beam Current mA 25

Pulse Length ms 1

Beam Intensity P / pulse 1.5E+14

P/hour 5.4E+18

Linac Beam Power MW avg. 2

MW peak 200

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Wide Range of Applications

~ 700m Active Length8 GeV Linac

X-RAY FEL LAB

Long-Pulse Spallation Source

8 GeVneutrino

MainInjector@2 MW

Anti-Proton

SY-120Fixed-Target

Neutrino“Super- Beams”

NUMI

Off- Axis

& Neutrino Target

Neutrinosto “Homestake”

Short Baseline Detector Array

Target and Muon Cooling Channel

Bunching Ring

RecirculatingLinac for Neutrino Factory

VLHC at Fermilab

Damping Ringsfor TESLA @ FNALWith 8 GeV e+ Preacc.

1% LC Systems Test

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Wide Range Choice of MI Beam Energy

Main Injector: 120 GeV, 0.67 Hz Cycle, 2.0 MW Beam PowerLinac Protons: 8 GeV, 4.67 Hz Cycle, 0.93 MW Beam Power Linac Electrons: 8 GeV, 4.67 Hz Cycle, 0.93 MW Beam Power

8 GeV Linac Cycles 1.5E14 per Pulse at 10Hz

Main Injector Energy

H-Injection

8 GeVProtons

8 GeVElectrons

0

20

40

60

80

100

120

140

0 0.5 1 1.5 2 2.5 3

Time (sec)

MI Energy

H- Injection

8 GeV Protons

Electrons

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Wide Range Choice of MI Beam Energy (cont…)

Main Injector: 40 GeV, 2.0 Hz Cycle, 2.0 MW Beam PowerLinac Protons: 8 GeV, 4.0 Hz Cycle, 0.8 MW Beam Power Linac Electrons: 8 GeV, 4.0 Hz Cycle, 0.8 MW Beam Power

8 GeV Linac Cycles 1.5E14 per Pulse at 10Hz

Main Injector Energy

H-Injection

8 GeVProtons

8 GeVElectrons

0

20

40

60

80

100

120

140

0 0.5 1 1.5 2 2.5 3

Time (sec)

MI Energy

H- Injection

8 GeV Protons

Electrons

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8 GeV Linac Baseline 2 MW

D T L 1D T L 2D T L 3D T L 4D T L 5D T L 6R F QR F Q

Modulator Modulator

(7 total) 402.5 MHzSNS Klystrons 2.5 MW

H -

B=0.47 B=0.47 B=0.61 B=0.61 B=0.61 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81

Modulator Modulator Modulator Modulator Modulator

12 cavites/ Klystron 8 cavites/ Klystron

805 MHz SNS Klystrons 5 MW

Warm CopperDrift Tube Linac402.5 MHz0 - 87 MeV

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator Modulator Modulator Modulator Modulator Modulator Modulator

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator Modulator Modulator

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator Modulator Modulator Modulator Modulator Modulator Modulator

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator Modulator Modulator

12 cavites/ Klystron

1207 MHz Beta=1

41 Klystrons (3 types) 31 Modulators 20 MW ea. 7 Warm Linac Loads 48 Cryomodules384 Superconducting Cavities

8 GeV 2 MW LINAC

Superconducting "SNS" Linac805 MHz0.087 - 1.2 GeV

"TESLA" LINAC 24 Klystrons288 cavites in 36 Cryomodules

10 Klystrons96 cavites in 12 Cryomodules

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0.5 MW with TESLA Frequencies & SCRF F.E.

R F QR F Q

Modulator

H -

B=0.47 B=0.47 B=0.61 B=0.61 B=0.61 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81 B=0.81

Modulator

"Pulsed RIA" SCRF Linac 325 MHz 0 - 120 MeV

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator

12 Klystrons (2 types) 11 Modulators 20 MW ea. 1 Warm Linac Load 54 Cryomodules~550 Superconducting Cavities

8 GeV 0.5 MW LINAC

8 Klystrons288 cavites in 36 Cryomodules

2 Klystrons96 cavites in 12 Cryomodules

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator

B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1B e t a = 1

Modulator Modulator

Modulator

48 cavites/ Klystron

36 cavites/ Klystron

TESLA Klystrons1300 MHz 10 MW

"Squeezed TESLA" Superconducting Linac1300 MHz 0.087 - 1.2 GeV

"TESLA" LINAC 1300 MHz Beta=1

S S RS S RS S RD S RD S RD S R

Multi-Cavity Fanout at 10-20kW/cavityPhase & Amplitude Adjust via Fast Ferrite Tuners

TESLA Klystrons1300 MHz 10 MW

325 MHz Klystrons1.5 MW

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RF Fanout

CIRCULATOR/ ISOLATOR

Magic Tee

FerriteLoaded Stub

CAVITYBEAM

1/8 Power Split (9.03 dB)

DIRECTIONAL COUPLER

1/7 Power Split (8.45 dB)

1/6 Power Split (7.78 dB)

1/5 Power Split (6.99 dB)

1/4 Power Split (6.02 dB)

1/3 Power Split (4.77 dB)

1/2 Power Split (3.01 dB)

E-H TUNER

KLYSTRON

35 footwaveguidefrom galleryto tunnel

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RF Fanout at Each Cavity

CIRCULATOR/ ISOLATOR

Magic Tee

FerriteLoaded Stub

CAVITYBEAM

DIRECTIONAL COUPLER

E-H TUNER

KLYSTRON

35 footwaveguidefrom galleryto tunnel

CIRCULATOR / ISOLATOR - Passes RF power forward towards cavity - Diverts reflected power to water cooled load

KLYSTRON - RF Power Source - Located in Gallery above tunnel - Each Klystron Feeds 8-16 Cavities

DIRECTIONAL COUPLER - Picks of a fixed amount of RF power at each station - Passes remaining power downstream to other cavities

E-H TUNER - Provides Phase and Amplitude Control for Cavities - Biased Ferrite Provides Electronic Control

SUPERCONDUCTING RF CAVITY - Couples RF Power to Beam

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ELECTRONICALLY ADJUSTABLEE-H TUNER

Magic Tee

MICROWAVE INPUT POWER from Klystron and Circulator

E-HTUNER

Reflected Power(absorbed by circulator)

ATTENUATED OUTPUT TO CAVITY

ELECTRONIC TUNINGWITH BIASED FERRITE

Bias Coil

FerriteLoadedStub

FERRITE LOADED SHORTED STUBSCHANGE ELECTRICAL LENGTH DEPENDING ON DC MAGNETIC BIAS.

TWO COILS PROVIDE INDEPENDENTPHASE AND AMPLITUDE CONTROL OF CAVITIES

Attractive Price Quote from AFT

(<< Klystron)

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Ferrite Phase Shifter High-Power Test

Stand

805 MHz Klystron 12 MW x 100usec

(need: 0.5 MW x 1 msec)

First goal: See if existing YIG tuner

functions at 500kW. (yes!)

Ultimate Goal:0.2 dB loss for360 deg. phase shiftin 100~500usec.Door-knob

Transition

YIG FerritePhase Shifter

Dry Load

FerriteBias

Supply

HybridTee

12 MW Klystron

A. Moretti, D. Wildman, N. Solyak, Y. Terechkine

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Main Injector Upgrade to 2 MW

Present Upgrade

Injection kinetic energy (GeV) 8 8

Extraction kinetic energy (GeV) 120 8 - 120

Protons per MI cycle 3  1013 1.5  1014

Cycle time at 120 GeV (s) 1.867 1.533

Beam power (MW) 0.3 1.9

• Increase beam intensity by a factor of 5

• Reduce cycle time by 20%

• Increase beam power by a factor of 6

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Technical Systems Upgrade

RF: major upgrade. Need a second power amplifier for each cavity and more cavities; also work on a new cavity design.

Power supply: moderate upgrade Magnet: ok Cooling capacity: ok for magnet, but need to be doubled for RF Gamma-t jump system: new Large aperture quadrupoles: new Shielding: ok Collimation system: new Passive damper and active feedback: new or moderate upgrade Kickers: moderate upgrade Abort system: moderate upgrade NuMI beamline: moderate upgrade

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Dual PA for MI RF Cavity

To be replaced by a 2nd PA

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New RF Design

Z0 = 20 , R= 100 k, Q = 4000, R/Q = 25 , V = 240 kV

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Large Aperture Quadrupole

Lamination design 3-D calculation

Fabricating 9 magnets, 7 to be installed in the MI in 2005

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Issues Concerning 8 GeV H Ions

OUTLINE 1. Introduction 2. Atomic Physics of 8 GeV H ions

2.1. General physics of H ions 2.2. Blackbody radiation stripping 2.3. Magnetic field stripping 2.4. Residual gas stripping 2.5. Lifetime of Stark states of hydrogen atoms 2.6. Population of Stark states of hydrogen atoms

3. Foil Physics 3.1. Stripping efficiency 3.2. Multiple Coulomb scattering 3.3. Large angle Coulomb scattering 3.4. Energy deposition and heating analysis (MARS) 3.5. Heating and stress analysis (ANSYS) 3.6. Radiation activation

4. Beam Physics of an 8 GeV H transport line 4.1. Collimation 4.2. Energy jitter correction 4.3. Radiation activation

5. Summary

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Blackbody Radiation Stripping

• At 8 GeV, thermal photons emitted from the room temperature beam pipe would cause a loss of ~ 0.53 × 106 m1 sec1

• Or about 0.53 × 108 particles m1 sec1

• High radiation activation on the beam pipe is a serious concern

Photodetachment of H- Ions from Blackbody Radiation (@ 300 K)

1.00E-11

1.00E-10

1.00E-09

1.00E-08

1.00E-07

1.00E-06

1.00E-05

0 10 20 30 40 50

H- ion kinetic energy (GeV)

Det

ach

men

t ra

te (

1/m

)

Hill-Bryant method

8 GeV

1 GeV

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Foil Stripping Efficiency Measurements

Webber & Hojvat, 1979

Fermilab linac, 200 MeV

Gulley et al., 1996

LANL linac, 800 MeV

11.2% H0

0.4% H0H0

H-

H+H+

H-

H0

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Foil Stripping Efficiency Calculation

H(0) Yield at Different Energies

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0 100 200 300 400 500 600

Foil Thickness (microgram/cm^2)

H(0

) Y

ield

8 GeV

800 MeV (Gulley et al.)

400 MeV

200 MeV (W&H)

200 MeV (fit to Gulley)

0.5% H0

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Summary

Proton driver and ILC are two candidates for a future construction project at Fermilab

The sc linac design is chosen. This has the major advantage of a large overlap in R&D for both candidates, e.g., SMTF

A key R&D item is the fast phase shifter

A comprehensive understanding of the transport and stripping of 8 GeV H ions is another high priority item

The lab has decided to work towards the goal of getting DOE’s CD0 approval next year.

Questions?