ILC Positrons

July 26, 2007 Toward the ILC

AmericasILC Positrons

J. C. Sheppard

SLAC

July 26, 2007

Positron Production for the ILC


Americas

Positron Production for the ILC

What is the ILC e+ System

How to make e+

Something about polarization

Who works on this stuff

What are the design issues

What next

Americas

Slide 3July 26, 2007 Toward the ILC

THE INTERNATIONAL LINEAR COLLIDER (ILC)

Parameter Parameter ReferenceReference Upgrade Upgrade

Beam Energy Beam Energy (GeV)(GeV) 250 250 500 500 RF gradient RF gradient (MV/m)(MV/m) 28 28 35 35 Two-Linac length Two-Linac length (km)(km) 27.00 27.00 42.54 42.54 Bunches/pulse Bunches/pulse 2625 2625 2625 2625 Particles/bunch Particles/bunch (10(101010)) 2 2 2 2 Beam pulse length Beam pulse length (µs )(µs ) 968 968 968 968 Pulse/s Pulse/s (Hz)(Hz) 5 5 5 5 xx(IP) (IP) (nm)(nm) 543 543 489 489 yy(IP) (IP) (nm)(nm) 5.7 5.7 4.0 4.0 zz(IP) (IP) (mm)(mm) 0.3 0.3 0.3 0.3 δδE E (%)(%) 3.0 3.0 5.9 5.9 Luminosity Luminosity (10(103333cmcm−2−2ss−1−1)) 25.625.6 38.138.1Average beam power Average beam power (MW)(MW) 22.6 22.6 45.2 45.2 Total number of klystrons Total number of klystrons 603 603 1211 1211 Total number of cavities Total number of cavities 18096 18096 29064 29064 AC to beam efficiency AC to beam efficiency (%)(%) 20.8 20.8 17.5 17.5

Parameter Parameter ReferenceReference Upgrade Upgrade

Beam Energy Beam Energy (GeV)(GeV) 250 250 500 500 RF gradient RF gradient (MV/m)(MV/m) 28 28 35 35 Two-Linac length Two-Linac length (km)(km) 27.00 27.00 42.54 42.54 Bunches/pulse Bunches/pulse 2625 2625 2625 2625 Particles/bunch Particles/bunch (10(101010)) 2 2 2 2 Beam pulse length Beam pulse length (µs )(µs ) 968 968 968 968 Pulse/s Pulse/s (Hz)(Hz) 5 5 5 5 xx(IP) (IP) (nm)(nm) 543 543 489 489 yy(IP) (IP) (nm)(nm) 5.7 5.7 4.0 4.0 zz(IP) (IP) (mm)(mm) 0.3 0.3 0.3 0.3 δδE E (%)(%) 3.0 3.0 5.9 5.9 Luminosity Luminosity (10(103333cmcm−2−2ss−1−1)) 25.625.6 38.138.1Average beam power Average beam power (MW)(MW) 22.6 22.6 45.2 45.2 Total number of klystrons Total number of klystrons 603 603 1211 1211 Total number of cavities Total number of cavities 18096 18096 29064 29064 AC to beam efficiency AC to beam efficiency (%)(%) 20.8 20.8 17.5 17.5

WORLD CollaborationWORLD CollaborationMulti-billion dollar projectMulti-billion dollar projectProposed eProposed e++ee–– linear collider linear collider0.5-1.0 TeV center-of-mass 0.5-1.0 TeV center-of-mass energiesenergiesMajor elementsMajor elements

Electron injectorElectron injectorElectron damping ringElectron damping ringMain electron linacMain electron linacElectron beam delivery to IRElectron beam delivery to IRPositron SourcePositron SourcePositron damping ring(s)Positron damping ring(s)Main positron linacMain positron linacPositron beam delivery to IRPositron beam delivery to IRIRIRDetectors at IRDetectors at IR


Americas

ILC Positron Source Parameters

Parameter Symbol Value Units

Bunch Population Nb 2x1010 #

Bunches per pulse nb 2625 #

Bunch spacing tb 369 ns

Pulse repetition rate frep 5 Hz

Injection Energy (DR) E0 5 GeV

Beam Power (x1.5) Po 300 kW

Polarization e-(e+) P 80(30) %


POSITRON SOURCE DESIGN ISSUES

Drive beamDrive beamElectrons or Electrons or photonsphotons

Photons allow for the possibility of polarized positronsPhotons allow for the possibility of polarized positrons

How are the photons madeHow are the photons madeMulti-hundred GeV electron beam through an undulatorMulti-hundred GeV electron beam through an undulatorCompton back-scattering laser beam on a multi-GeV electron beamCompton back-scattering laser beam on a multi-GeV electron beam

Drive beam phase spaceDrive beam phase space

TargetTargetChoice of materialChoice of materialTarget heat/shock/stressTarget heat/shock/stress

Positron capturePositron captureBeam heatingBeam heatingCapture RFCapture RFCapture magnetic fieldCapture magnetic fieldDamping ring acceptanceDamping ring acceptance

Target vaultTarget vault

Drive beamDrive beamElectrons or Electrons or photonsphotons

Photons allow for the possibility of polarized positronsPhotons allow for the possibility of polarized positrons

How are the photons madeHow are the photons madeMulti-hundred GeV electron beam through an undulatorMulti-hundred GeV electron beam through an undulatorCompton back-scattering laser beam on a multi-GeV electron beamCompton back-scattering laser beam on a multi-GeV electron beam

Drive beam phase spaceDrive beam phase space

TargetTargetChoice of materialChoice of materialTarget heat/shock/stressTarget heat/shock/stress

Positron capturePositron captureBeam heatingBeam heatingCapture RFCapture RFCapture magnetic fieldCapture magnetic fieldDamping ring acceptanceDamping ring acceptance

Target vaultTarget vault

Americas


ILC Layout

ee++ & e & e- - Damping Rings centrally locatedDamping Rings centrally located

positron source uses 150 GeV electron beampositron source uses 150 GeV electron beam

L-band superconducting RF for accelerationL-band superconducting RF for acceleration

ee++ & e & e- - Damping Rings centrally locatedDamping Rings centrally located

positron source uses 150 GeV electron beampositron source uses 150 GeV electron beam

L-band superconducting RF for accelerationL-band superconducting RF for acceleration

Americas



POSITRON PRODUCTION SCHEMES – DRIVE BEAMS

EM Shower

e+ to damping ringsConventional

Undulator-based (from USLCTOS)

W-Re Target

6 GeV e-


COMPTON-BASED POSITRON SOURCE – LASERS

GLC laser power : 9.8 MW peak power per laser bunch ~ 400 kW average power (40kW with use of mirrors)~ 73 GW peak power

ILC bunch structure 2820 * 5 ~= 95 * 150but 2820 bunch pulse trainsmay be able to use mirrors to relax laser parameters


Snowmass 2005 Ring based Compton


ERL based Compton scheme & requirements to lasers

PosiPol2007@LAL23/May/2007

Tsunehiko OMORI (KEK)my talk is inspired by Variola-san's talk at KEK Nov/2006 and Rainer-san's suggestion at SLAC Apr/2004


UNDULATOR BASED POSITRON SOURCE

Need to use ILC electron beam – possible reliability, machine development and commissioning issues

Can use electron source for commissioning

Long helical undulator, small aperturepermanent magnetwarm pulsedsuperconducting


AmericasPositron Source Layout


Americas

Polarized Positrons from Polarized ’s

(Olsen & Maximon, 1959)

Circular polarization of photon transfers to the longitudinal polarization of the positron.

Positron polarization varies with the energy transferred to the positron.


AmericasPhoton Intensity, Angular Dist., Number,

Polarization


AmericasPolarized Positron Production in the

FFTB

Polarized photons pair produce polarized positrons in a 0.5 r.l. thick target of Ti-alloy with a yield of about 0.5%.

Longitudinal polarization of the positrons is 54%, averaged over the full spectrum

Note: for 0.5 r.l. W converter, the yield is about 1% and the average polarization is 51%.


AmericasPhoton Number Spectrum

Number of photons per e- per 1m undulator:Old BCD: 2.578UK1: 1.946; UK2: 1.556; UK3: 1.107Cornell1: 0.521; Cornell2: 1.2; Cornell3: 0.386

Gai and Liu, ANL


AmericasPhoton Spectrum and Polarization of ILC baseline

undulatorResults of photon number spectrum and polarization characteristic of ILC undulator are given here as examples. The parameter of ILC undulator is K=1, u=1cm and the energy of electron beam is 150GeV.

Figure1. Photon Number spectrum and polarization characteristics of ILC undulator up to the 9th harmonic. Only those have energy closed to critical energy of its corresponding harmonics have higher polarization Gai and Liu, ANL


AmericasInitial Polarization of Positron beam at Target

exit(K=0.92 u=1.15)

Gai and Liu, ANL


Americas

Gai and Liu, ANL

ILC Positron Polarization,captured~ 30% Pol


AmericasILC Positron Polarization

In the case of the ILC baseline, the composite polarization of the captured positrons is about 30%. Spin rotation to preserve the polarization in the damping ring(s) is included

To upgrade to higher polarization, the incident photon beam is collimated to remove the low energy, reversely polarized component of the spectrum ( = 1.414). The length of the undulator needs to be increased to compensate for the loss in absolute flux.


AmericasUS Institutions

• Institutions doing substantial work on ILC e+ development– SLAC

• overall coordination & leadership for the RDR• define parameters• target hall, remote handling, activation• beamline optics and tracking• NC L-Band accelerator structures and RF systems• Experiments – E166, FLUKA validation experiment

– LLNL• target simulations (thermal hydraulics and stress, rotordynamics, materials)• target design (testing and prototyping)• pulsed OMD design

– ANL• optics• tracking• OMD studies• eddy current calculations

– Cornell• undulator design, alternative target concepts


AmericasEuropean Institutions

• Institutions doing substantial work on ILC e+ development– Daresbury Laboratory

• EDR leadership• undulator design and prototyping• beam degradation calculations

– Rutherford-Appleton Laboratory• remote handling• eddy current calculations• target hall activation

– Cockcroft and Liverpool University• target design and prototyping

– DESY-Berlin• target hall activation• spin preservation• photon collimation• E166


AmericasILC e+ Collaboration Meeting


AmericasILC Polarized Positron System Technical Issues

1. Demonstrate undulator parameters

2. Demonstrate NC SW structure hi power rf performance

3. Spinning target pre-prototype demonstration

3. Eddy current measurements on spinning target

4. Selection and Technical design of Optical Matching Device

5. System engineering for e+ source remote handling

6. System engineering for photon dump

7. System design compatibility with ILC upgrade scenarios: polarization and energy


AmericasILC Positron EDR Milestones

• Sep 07: Full layout with /4 XMFR OMD

• Dec 07: EDR Scope definition: design depth and breadth, cost, schedule, staff

• Jun 08: Full upgrade scenario: polarization and ILC energy

• Sep 08: OMD selection (dc immersed, pulsed FC, /4 XMFR), Und parameter selection

• Dec 08: Freeze layout, full component and civil specifications (yield, overhead, remote handling, upgrades)

• Jan 09: EDR detailed component inventory

• May 09: First cost review

• Dec 09: Deliver EDR and preconstruction work plan


AmericasILC Positron Design Issues, Undulator

Ne+ = cYLunNe-

c (Adr,Edr,Ac,e+) ~ 15%-25%

Y(E, X0,) ~ 1%-5%

n(K,u) ~ 2

Lu ~ 100 m


AmericasILC Positron Design Issues, Target

FOM =[E/2(1-)/Cv/]/UTS(fatigued)

Thermoelastic stress wrt material strength

Targets break rather than melt

E/mass < 100 J/g

High strength Ti-alloy (Ti6%Al4%V)


AmericasILC Positron Design Issues, Target

Need to spread out the energy deposition

This is done by spinning the target at 100 m/s

Same problem with windows but do not know how to spin

Can imagine an entrance window

Exit window will not survive

July 26, 2007 Toward the ILC 30

ILC RDR Baseline Positron Source

RDR Parameters

Centre of undulator to target: 500m

Active (K=0.92, period=1.21mm) undulator: 147m

Photon beam power: 131kW

Beam spot: >1.7 mm rms


Baseline Target Design• Wheel rim speed (100m/s) fixed by thermal load (~8% of photon beam power)

•Rotation reduces pulse energy density from ~900J/g to ~24J/g

•Cooled by internal water-cooling channel

•Wheel diameter (~1m) fixed by radiation damage and capture optics

•Materials fixed by thermal and mechanical properties and pair-production cross-section (Ti6%Al4%V)

•Wheel geometry (~30mm radial width) constrained by eddy currents.

•20cm between target and rf cavity.

T. P

igg

ott, L

LN

L

Drive motor and water union are mounted on opposite ends of through-shaft.


AmericasTarget Progress

• Baseline target/capture

– RAL, ANL and Cornell have done Eddy current simulation which produce consistent results with multiple codes. Estimates for power dissipation in the target are >100kW for a constant field and are considered excessive.

– Evaluation of ceramic target material is on-going. No conclusions.– Radiation damage of the superconducting coil is still TBD but may not

be worthwhile unless a solution can be found for the eddy currents.– ANL simulation of beam heating in windows shows that an upstream

window is feasible but a downstream window is not.

• Alternative target/capture

– Capture efficiency for the lithium lens focusing and ¼ wave solenoid is still TBD

– Thermal heating and stress for the lithium lens is still on-going.– Thermal stress calculation for the liquid metal target is still on-going


Americas

Capture versus Optical Matching Device Type

From F. Zhou, W. Liu

Pos

itron

Cap

ture

(ar

b. u

nits

)

No OMD

¼ xfrm

Pulsed FC

Immersed

0

0.1

0.2

0.3

0.4


AmericasOptical Matching Device (OMD)

• Optical Matching Device – factor of 2 in positron yield (3 if immersed target)

– DC solenoid before target or pulsed flux concentrator after target

– Pulsed device is the baseline design

• Target spins in the magnetic field of the OMD– Eddy currents in the target – need to calculate power

– Magnetic field is modified by the eddy currents – effect on yield??

• Eddy current mitigation– Reduce amount of spinning metal

– Do experiment to validate eddy current calculations

– Look for low electrical / high thermal conductivity Ti-alloys

– Other materials such as ceramics

– No OMD• Use focusing solenoidal lens (1/4 wave) – lower fields• OMD is upgrade to polarization(??)


AmericasEddy Current Experiment

Eddy current calculation mesh -

S. Antipov, W. Liu, W. Gai - ANL

Proposed experimentLayout at CockcroftInstitute/Daresbury(this summer)


AmericasCalculated Eddy Current Power

0

500

1000

1500

2000

2500

0 500 1000 1500 2000 2500 3000 3500

RPMs

Power, kWatts σ=2.5e6

σ=2.0e6

σ=1.5e6

σ=1.0e6

coppersigma=60e6

Nominal RPMs

TiAlV = 6e5


Americas

Pulsed Flux Concentrator: 7T, 1 ms, 5 Hz

Pulsed Flux Concentrator, circa 1965: Brechna et al.


AmericasOMD Progress

• Plans and Actions (baseline target/capture):– ANL will simulate eddy currents in the pulsed magnet configuration.

– UK will evaluate suitability of non-conducting materials for the target

– Daresbury/Cockroft/RAL will spin a one meter target wheel in a constant magnetic field and will measure the forces.

• Eddy simulations will be calculated and benchmarked against this configuration

• Plans and Actions (alternative targets/capture):– ANL will determine the capture efficiency for ¼ wave focusing optics

and lithium lens.

– LLNL will evaluate the survivability of lithium lens to beam stress

– Cornell will specify an initial design of a liquid metal target. LLNL will calculate the Stress-strain behavior of the outgoing beam window.


CCLRC

Undulator Challenges

High fields Pushing the limits of technology

Short Periods Shorter periods imply higher fields

Narrow apertures Very tight tolerances - Alignment critical

Cold bore (4K surface) Cannot tolerate more than few W of heating per module

Minimising impact on electron beam Must not degrade electron beam properties but have to remove energy from

electrons Creating a vacuum

Impossible to use conventional pumps, need other solution Minimising cost

Minimise total length, value engineering

High fields Pushing the limits of technology

Short Periods Shorter periods imply higher fields

Narrow apertures Very tight tolerances - Alignment critical

Cold bore (4K surface) Cannot tolerate more than few W of heating per module

Minimising impact on electron beam Must not degrade electron beam properties but have to remove energy from

electrons Creating a vacuum

Impossible to use conventional pumps, need other solution Minimising cost

Minimise total length, value engineering


CCLRC

UK Undulator Recent Highlights

Two 12mm period SC undulator prototypes built and tested Period reduced to 12mm from 14mm Better, more reproducible, fabrication technique Full inclusion of iron for the first time

One 11.5mm period SC undulator built and tested Period further reduced to RDR value of 11.5mm New SC wire used (more SC and less Cu) Field strength measured greater than expected, possibly due to increase in SC

content of wire Best ever field quality results (well within spec) Full length prototype will use these parameters

Full length prototype construction started 4m prototype design complete Fabrication has commenced

Undulator impact studies ongoing Emittance growth due to misalignments & wakefields shown to be <2%

Paper on undulator technology choice published by Phys. Rev. ST-AB Paper on vacuum issues submitted to JVSTA

Two 12mm period SC undulator prototypes built and tested Period reduced to 12mm from 14mm Better, more reproducible, fabrication technique Full inclusion of iron for the first time

One 11.5mm period SC undulator built and tested Period further reduced to RDR value of 11.5mm New SC wire used (more SC and less Cu) Field strength measured greater than expected, possibly due to increase in SC

content of wire Best ever field quality results (well within spec) Full length prototype will use these parameters

Full length prototype construction started 4m prototype design complete Fabrication has commenced

Undulator impact studies ongoing Emittance growth due to misalignments & wakefields shown to be <2%

Paper on undulator technology choice published by Phys. Rev. ST-AB Paper on vacuum issues submitted to JVSTA


CCLRC

UK Prototypes

I II III IV V

Former material Al Al Al Iron Iron

Period, mm 14 14 12 12 11.5

Groove shape rectangular trapezoidal trapezoidal trapezoidal rectangular

Winding bore, mm

6 6 6.35 6.35 6.35

Vac bore, mm 4 4 4 4.5

(St Steel tube)

5.23*

(Cu tube)

Winding 8-wire ribbon,

8 layers

9-wire ribbon,

8 layers

7-wire ribbon,

8 layers

7-wire ribbon,

8 layers

7-wire ribbon,

8 layers

Sc wire Cu:Sc 1.35:1 Cu:Sc 1.35:1 Cu:Sc 1.35:1 Cu:Sc 1.35:1 Cu:Sc 0.9:1

Status Completed and tested

Completed, tested and sectioned

Completed and tested




CCLRC

Prototype 5

Same parameters as RDR Baseline undulator

11.5 mm period 6.35 mm winding diameter Peak on-axis field spec of

0.86T (10 MeV photons) Winding directly onto copper

tube with iron pole and yoke New wire with more

aggressive Cu:SC ratio of 0.9:1.0

Same parameters as RDR Baseline undulator

11.5 mm period 6.35 mm winding diameter Peak on-axis field spec of

0.86T (10 MeV photons) Winding directly onto copper

tube with iron pole and yoke New wire with more

aggressive Cu:SC ratio of 0.9:1.0

First 500mm long

prototype


CCLRC

1st results from prototype 5 at RAL

Prototype V fi eld profi le

-1

-0.5

0

0.5

1

0 100 200 300 400 500

Z, mm

Fie

ld o

n ax

is, T

Prototype 5 details

Period : 11.5 mmMagnetic bore: 6.35 mmConfiguration: Iron poles and yoke

Measured field at 200A

0.822 T +/- 0.7 %(spec is +/- 1%)

Measurements for Prototype 5

Prototype V training

0

50

100

150

200

250

300

350

0 2 4 6 8 10 12

Magent runup

Que

nch

curr

ent (

A)

23/01/2007

25/01/2007

Quench current 316A

Equates to a field of 1.1 T in bore

RDR value is 0.86 T

80% of critical current (proposed operating point) would be 0.95 T


CCLRC

Summary of Prototype Results

Field on axis vs. Undulator period

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

6 8 10 12 14 16 18

Period, mm

Fie

ld o

n a

xis,

T

K=1

10.7 MeV -photons

Achieved with Al-former(Prototype I)

Achieved with Al-former(Prototype III)

Achieved with iron former(Prototype IV)

Achieved with iron formerand iron yoke (Prototype IV)

Achieved with Prorotype V(iron former and iron yoke)

Aluminium former

Fe former

Fe former & yoke

Prototype 5 @ 250A

@ 200A


CCLRC

Specification for 4m Undulator Module

On axis field 0.86 T

Peak to peak variation <1%

Period 11.5 mm

Nominal Current ~250 A

Nom current as % of Short Sample 80%

SC wire NbTi 0.4mm dia., SC:Cu ratio 0.9:1

Winding Cross Section 7 wires wide x 8 high

Number of magnets per module 2 (powered separately for tests)

Length of magnetic field 2 x 1.74 m

No Beam Collimators or Beam Pipe Vacuum pumping ports in the magnet beam pipe


CCLRC

4m Prototype Module

Stainless steel vacuum vessel with Central turret

Stainless steel vacuum vessel with Central turret

50K Al Alloy Thermal shield. Supported from He bath

Stainless Steel He bath filled with liquid Helium.

Magnet support provided by a stiff U Beam

U beam Support rod

Superconducting Magnet cooled to 4.2K

Beam Tube

Construction has started, will be complete by Autumn 07


CCLRC

Magnet Design Concept

2 start helical groove machined in steel former

2 start helical groove machined in steel former

Cu beam pipe, withconductor wound on to tube OD

Steel Yoke. Provides 10% increase in field and mechanical support for former

PC board for S/C ribbon connections

Winding pins

Steel yoke


Americas

STATUS OF CORNELL UNDULATOR PROTOTYPING

Alexander Mikhailichenko, Maury Tigner

Cornell University, LEPP, Ithaca, NY 14853

A superconducting, helical undulator based source has been selected as the baseline design for the ILC. This report outlines progress towards design, modeling and testing elements of the needed undulator. A magnetic length of approximately 150 m is needed to produce the desired positron beam. This could be composed of about 50 modules of 4 m overall length each.This project is dedicated to the design and eventual fabrication of one full scale, 4 m long undulator module. The concept builds on a copper vacuum chamber of 8 mm internal bore


Americas

Fig.1;Extensible prototype concept for ILC positron undulator . Diameter of cryostat =102mm


Americas

Several 40 cm long undulator models with 10 and 12 mm period, Ø 8 mm clear bore have been made and measured. See Table

OFC vacuum chamber, RF smoothness

For aperture diameter 5.75 mm we expect: for period 8mm – K~0.4 ; for period 10mm -K~0.9

SC wire 54 filaments 56 filaments 56 filaments

# layers 5* 6* 9** (12***) +sectioning

λ=10 mm K=0.36 tested K=0.42 tested K≈0.5 (calculated)

λ=12 mm K=0.72 tested K=0.83 tested K≈1 (calculated)

*) Wire – Ø0.6 mm bare; **) Wire – Ø0.4 mm bare; ***) Wire – Ø0.3 mm bare

Fig.3: Field profile – conical ends. 6 layer, 12 mm period – orthogonal hall probes. 1Tesla full scale


Americas

•Progress to Date

•An overall concept design for the module as shown in Fig. 1 has been developed. The design is very compact, having an outside cryostat diameter of 100 mm. Standard size plumbing components are used throughout. Figure 1 shows the cross section design for tapered end coils.

•We have made optimization studies for undulators having 10 and 12 mm period with 8 mm clear bore and wound with various commercially available wires.

•Technology for fabrication of the undulator has been reduced to practice including winding of the wire and the helical iron yoke as well as procedures and apparatus for measuring the field distribution at the operating temperature. •Several 40 cm long undulator models with 10 and 12 mm period, 8 mm clear bore have been made and measured.


Americas

Capture versus initial rf gradient

Initial rf gradient (MV/m)

Pos

itron

Cap

ture

(ar

b. u

nits

)

Batygin slac-pub-11238


AmericasPrototype Positron Capture Section


AmericasPreliminary Microwave Checking

1300.175 MHz at 20°C, N2

1300.125 MHz at 20°C, N2

Field Plots for Bead Pulling Two Different Frequencies Showing the Correct Cell Frequency and Tuning Property.

Measurement Setup for the Stacked Structure before Brazing without Tuning


Americas

Brazed Coupler and Body Subassemblies - Ready for Final Brazing


AmericasSummary Page for the Capture RF

Juwen Wang

• Vacuum Leak Check• Recheck the RF Properties• Installation:

• Support;• Cooling system;• Waveguide system;• Window; • Vacuum system; • Solenoid; • Monitoring System.

• High Power Test (5MW, 1.2 ms,5 Hz)• Beam Acceleration Test


AmericasOptics

• Source optics laid out. Need to look at details– Beam loss and collimation

– Component interferences (target halls, DR injection)

– Refine and document optics and beam physics

58 EPAC June 2003

E-166 Experiment

E-166 is a demonstration of undulator-based polarized positron production for linear colliders

- E-166 uses the 50 GeV SLAC beam in conjunction with 1 m-long, helical undulator to make polarized photons in the FFTB.- These photons are converted in a ~0.5 rad. len. thick target into polarized positrons (and electrons).- The polarization of the positrons and photons will be measured.

59 EPAC June 2003

Undulator-Based Production of Polarized Undulator-Based Production of Polarized PositronsPositrons

E-166 Collaboration

(45 Collaborators)

60 EPAC June 2003

Undulator-Based Production of Polarized Undulator-Based Production of Polarized PositronsPositronsE-166 Collaborating Institutions

(15 Institutions)


Americas


AmericasFLUKA Validation Experiment


AmericasFLUKA Validation Experiment

• SLAC/CERN Collaboration (RP groups) – Validation of FLUKA activation calculations

• 100 W

• 30 GeV electron beam in ESA at SLAC

• Cylindrical copper dump

• Samples around the dump (including a Ti-4V-6Al)

• Look mr/hour and gamma spectrum from irradiated samples

– Run at the beginning of April …


AmericasExperiment Setup


AmericasPreliminary Data: Ti and Ti-alloy


Americas

Target Hall / Remote Handling

• Projected ILC running mode– 9 month run + 3 month shutdowns

• Target stations designed with 2 year lifetime– Replace target station every shutdown– If target fails then

• EITHER a “hot” spare• OR fast replacement

• Radiation levels ~ 100 rem/hour immediately after beam shutoff– Remote handling needed

• Target hall deep underground– Vertical target extraction/replacement

• Vinod used to work in the FNAL antiproton source!!


Americas

ILC Target Hall Cartoon (single target)


AmericasTarget Remote Handling

Estimated 53 hour replacement time


M. W

oodward, R

AL

Cryocooler

(if required)

+ vacuum pump

+ water pump

Details of vertical drive for target wheel not yet considered.

Remote-Handling Module and Plug

Module contains target, capture optics and first accelerating cavity.


Americas

TRIUMF – ISAC FACILITY


AmericasVisit to ORNL


AmericasVisit to ORNL

• The remote handling systems for the SNS target is estimated to have cost about $100M

• Off the cuff estimate to work up ILC e+ Remote Handling Systems for the EDR would be about 4-5 FTE spread out over 3 years

Americas


ILC Status

Reference Design Report (RDR) completedReference Design Report (RDR) completedDesign feasibility Design feasibility

Alternative technologies (cost saving, risk reduction ..)Alternative technologies (cost saving, risk reduction ..)

R&D prioritiesR&D priorities

4-volume report, Executive Summary, Physics Case, 4-volume report, Executive Summary, Physics Case, Accelerator, Detectors ~ 700 pages producedAccelerator, Detectors ~ 700 pages produced

Printed version in AugustPrinted version in August

Now setting up Engineering Design Phase (EDR)Now setting up Engineering Design Phase (EDR)Define EDR, (nn% design complete?)Define EDR, (nn% design complete?)

Choose final design technologiesChoose final design technologies

Setup structure to get it done (regional balance to optimize Setup structure to get it done (regional balance to optimize use of resources)use of resources)

Three year timescaleThree year timescale

Reference Design Report (RDR) completedReference Design Report (RDR) completedDesign feasibility Design feasibility

Alternative technologies (cost saving, risk reduction ..)Alternative technologies (cost saving, risk reduction ..)

R&D prioritiesR&D priorities

4-volume report, Executive Summary, Physics Case, 4-volume report, Executive Summary, Physics Case, Accelerator, Detectors ~ 700 pages producedAccelerator, Detectors ~ 700 pages produced

Printed version in AugustPrinted version in August

Now setting up Engineering Design Phase (EDR)Now setting up Engineering Design Phase (EDR)Define EDR, (nn% design complete?)Define EDR, (nn% design complete?)

Choose final design technologiesChoose final design technologies

Setup structure to get it done (regional balance to optimize Setup structure to get it done (regional balance to optimize use of resources)use of resources)

Three year timescaleThree year timescale


Americas

What do we want

• RDR to EDR phase– ILC “management” is trying to match ILC tasks to world wide

ILC resources– ILC positron source EDR leadership may well migrate to

Europe– Strong US input is still needed to finish EDR

• Design of all aspects of the ILC e+ Sub-systems needs help– Need people to consult with – Need collaborators to help with design– Need collaborators to take the lead in the design– Need collaborators to do the design


AmericasPolarized Electron Source

(A. Brachmann, SLAC)


Americas

Select Positron References, 1

• ILC RDR Positron Chapter:

http://media.linearcollider.org/report-apr03-part1.pdf sec. 2.3, pg. 45 ff• ILC Positron Source Collaboration Meetings

1st meeting at RAL September, 2006: http://www.te.rl.ac.uk/ILC_Positron_Source_Meeting/ILCMeeting.html

2nd meeting at IHEP, Beijing January, 2007 : http://hirune.kek.jp/mk/ilc/positron/IHEP/• ILC Notes

1. ILC Target Prototype Simulation by Means of FEM Antipov, S; Liu, W; Gai, W [ILC-NOTE-2007-011] http://ilcdoc.linearcollider.org/record/6949

2. On the Effect of Eddy Current Induced Field , Liu, W ; Antipov, S; Gai, W [ILC-NOTE-2007-010] http://ilcdoc.linearcollider.org/record/6948

3. The Undulator Based ILC Positron Source: Production and Capturing Simulation Study – Update,

Liu, W ; Gai, W [ILC-NOTE-2007-009] http://ilcdoc.linearcollider.org/record/6947• Other Notes

1. F.Zhou,Y.Batygin,Y.Nosochkov,J.C.Sheppard,and M.D.Woodley,"Start-to-end beam optics development and multi-particle tracking for the ILC undulator-based positron source", slac-pub-12239, Jan 2007. http://www.slac.stanford.edu/cgi-wrap/getdoc/slac-pub-12239.pdf

2. F.Zhou,Y.Batygin,A.Brachmann,J.Clendenin,R.H.Miller,J.C.Sheppard,and M.D.Woodley,"Start-to-end transport design and multi-particle tracking for the ILC electron source", slac-pub-12240, Jan 2007. http://www.slac.stanford.edu/cgi-wrap/getdoc/slac-pub-12240.pdf

3. A.Mikhailichenko, " Liquid metal target for ILC*."*. Jun 2006. 3pp.Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, 26-30 Jun 2006.Published in *Edinburgh 2006, EPAC* 816-818


Americas

Select Positron References, 2• Other Notes, cont’d

4. A.A. Mikhailichenko <http://www-spires.slac.stanford.edu/spires/find/wwwhepau/wwwscan?rawcmd=fin+%22Mikhailichenko%2C%20A%2EA%2E%22>, "Test of SC undulator for ILC.",Jun 2006. 3pp. Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, 26-30 Jun 2006.Published in *Edinburgh 2006, EPAC* 813-815.

5. A.Mikhailichenko, "Issues for the rotating target", CBN-07-02, 2007, http://www.lns.cornell.edu/public/CBN/2007/CBN07-2/CBN07-2.pdf

6. A.Mikhailichenko, "Positron Source for ILC:A perspective", CBN-06-06, 2006, http://www.lns.cornell.edu/public/CBN/2006/CBN06-1/CBN06-1.pdf

7. Preliminary Investigations of Eddy Current Effects on a Spinning Disk, W.T. Piggott, S. Walston, and D. Mayhall. UCRL-TR-224467, Sep. 8, 20068. Positron Source Target Update, W.T. Piggott, UCRL-PRES-227298, Jan. 16, 2007.9. Computer Calculations of Eddy-Current Power Loss in Rotating Titanium Wheels and Rims in

Localized Axial Magnetic Fields. D.J. Mayhall, W. Stein, and J. Gronberg, UCRL-TR-221440, May 17, 2006

10. A Preliminary Low-Frequency Electromagnetic Analysis of a Flux Concentrator, D.J. Mayhall, UCRL-TR-221994, June 13, 2006

Also see Posipol 2007 and Posipol 2006:

http://events.lal.in2p3.fr/conferences/Posipol07/

http://posipol2006.web.cern.ch/Posipol2006/

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