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R&D status of ILC Positron Source KURIKI Masao (Hiroshima/KEK) 구리기 마사오 ( 히로시마 대학 ). Table of Contents. Introduction RDR baseline configuration and its R&D. Alternative configuration and its R&D. TDP for ILC positron source Summary. ILC and Positron Source. - PowerPoint PPT Presentation
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ASIA ILC R&D seminarKympok National University, Taegu, Korea 129-30 October 2008
R&D status of ILC Positron Source
KURIKI Masao (Hiroshima/KEK)구리기 마사오 ( 히로시마 대학 )
ASIA ILC R&D seminarKympok National University, Taegu, Korea 229-30 October 2008
Table of Contents
IntroductionRDR baseline configuration and its R&D. Alternative configuration and its R&D.TDP for ILC positron sourceSummary
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 329-30 October 2008
ILC and Positron Source
Parameter Value# of positron/bunch 2.00E+10Bunch spacing 369ns# of bunch/Pulse 2625Pulse repetition rate 5Hz
I ntroduction
Baseline
Alternative
TDP
SummaryUndulator is the baseline design. Two alternatives:─ Conventional (electron driven) is a fall back.─ Laser Compton is an advanced alternative.
Any schemes are not fully established. Need a certain amount of R&D for ILC positron source.
ASIA ILC R&D seminarKympok National University, Taegu, Korea 429-30 October 2008
Baseline Design
It relies upon gamma rays generated by passing 150 GeV electron through 168m undulator.Undulator is “inserted” to part way of ML (150GeV).A positron source driven by 0.5 GeV electron is a back up for high availability and machine commissioning.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 529-30 October 2008
Undulator Parameters
Parameter ValueElectron drive energy 150 GeVElectron beam energy loss 4.5 GeVUndulator length 147 m (168m)Undulator period 11.5mmUndulator Field 0.86 TUndulator strength 0.92
10 MeVPhoton energy (1st hrmc)
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 629-30 October 2008
R&D efforts for the baseline (1)This system is a totally new approach; Feasibility of the system should be confirmed in various levels.─ Devices ─ System and sub-system
In addition, the ILC baseline e+ source is not an isolated system from the whole ILC and has inter-system dependencies.Careful considerations are necessary from the system point of view.─ E+ is generated at the same time for the collision. ─ E+ time structure is identical to that in ML.
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 729-30 October 2008
R&D efforts for the baseline (2)The R&D efforts for critical devices are on going.─ Super-conducting helical undulator.─ Rotating conversion target.─ Capture devices (pending due to no budget).
Several considerations from the system engineering point of view have been made. ─ E+ timing issue : a mathematical puzzle among DR
harmonic number, bunch spacing in ML, round trip duration from e- DR to e+ DR, etc.
─ Keep Alive e+ source : machine commissioning, fast recovery from the system failure,etc.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 829-30 October 2008
Undulator Cryo-module OverviewStainless steel vacuum vessel with Central turret
50K Al Alloy Thermal shield. Supported from He bath
Stainless Steel He bath contains100L liq He. Supported by 4 rods attached to the vacuum vessel
U Beam used to support/align the magnet.
U beam Support rod
Magnet cooled to 4.2K by liq He in bath.
Beam Tube
S Carr
ASIA ILC R&D seminarKympok National University, Taegu, Korea 929-30 October 2008
Undulator Cryomodule
U Beam
He Vessel
Heat Shield
Helical Undulator
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1029-30 October 2008
0
50
100
150
200
250
300
350
0 10 20 30 40
Quench number
Que
nch
curr
ent (
A)
magnet 1
magnet 2
nominal current
Quench Test & Field Measurement
All two magnets finally satisfied the specification.Field profile is measured by hall probe, showing a good quality.
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1129-30 October 2008
Conversion TargetK
en D
avie
s -
Dar
esbu
ry L
abor
ator
y
Water-cooled electromagnet Variable pole gap (0mm to 160mm) Peak field > 1 T at wheel
15 kW drive motor
Ti alloy wheel.
L Jenner
Torque Sensor
Photon beam
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1229-30 October 2008
Target Prototype
Experiment will start when personnel guards are in place
Should be completed by end of 2008
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1329-30 October 2008
Matching Device
The generated positrons is a point like with a large transverse momentum spread. That should be converted to a parallel beam for further acceleration; The matching device does it. Depending on the matching device, it increases capture efficiency from 10% to 40%.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1429-30 October 2008
DC Solenoid
High field (6T) and high capture efficiency(30%). Similar to other DC SC magnets; It is technically matured. It is not feasible for ILC since 100's of kW of eddy current in a fast rotating metal target.
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1529-30 October 2008
Shielded Flux Concentrator
Ramping from 0T to 7 T in 2cm (no field on target).Capture Efficiency ~21%Difficult technically to sustain 1ms pulse train length.Further study needed to prove feasibility (prototype).
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1629-30 October 2008
Quarter Wave Transformer
Ramping from 0T to 1 T in 5cm (no field on target).Capture efficiency ~ 15%. Technically matured and realizable (actual baseline).
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1729-30 October 2008
Summary for baseline
R&D efforts for critical devices are in progress (undulator, target, etc).Although Matching device is one of the most important, the R&D is stopped. QWT is the only realistic solution at this moment and it should be actual baseline as long as there is no big progress on R&D for MD.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1829-30 October 2008
Alternative Design
e- driven scheme (conventional) and Laser Compton scheme are considered to be alternative schemes. ─ e- driven scheme is a back-up alternative.─ Laser Compton is an advanced alternative.
Because the baseline design is a totally new approach, a conservative alternative is very important as a technical backup.Laser Compton is attractive, but it is technically immature; It is advanced alternative.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 1929-30 October 2008
e- driven schemee- drive beam impinges on a conversion target. ─ 6 GeV 2E+10 e- bunch.─ Amorphous W (W-Re alloy), crystalline W, diamond, liquid Pb-
Sn,etc.
Capture devices.
E+ booster up to 5 GeV: The technology depends on the pulse structure; SC for long pulse case (~1ms) and NC for short pulse case (<50μs).
The most important and difficult issue is conversion target.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2029-30 October 2008
CHANNELING FOR ILC & CLIC e+ source
R. ChehabA single target works for CLIC, but multi-target is needed for ILC limited by PEDD.A single target might work for ILC in Low P parameter.
e-
Crystal Amorphous
e+, e-, γe-
e+
“x” meters
Only the photons are impinging on the converter: that limits the energy deposition in the amorphous target.
Radiator Converter
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2129-30 October 2008
Driving motor
Vacuum pump
Cog-wheel pump
transport tubes
Target head
Liquid lead targetA prototype in BINP has been operated 20000h without any troubles. ─ Pb 90% Sn 10%, 300˚C, Cog-
wheel pump.Brazing technique for BN window has been established.
Liquid Pb-Sn jet in vacuum
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2229-30 October 2008
Laser Compton SchemeA few GeV (1.8GeV for example) electron bunch collides with 1μm laser photon stored in optical cavity. Several 10s MeV gamma impinges in a conversion target. A dedicated electron driver is reasonable. Obtaining enough positron, is a technical challenge.─ High intensity electron beam: Linac, Storage ring, ERL─ High intensity photon beam: High power laser, optical
cavity. ─ Stacking scheme: DR stacking, Pre-DR, etc.
I ntroduction
Baseline
Alternative
TI P
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2329-30 October 2008
Compton RingA storage ring for electron driver:5.3nC, 6.2ns, 1ps, 1.8GeV, 0.6Jx5CP.Positron bunch(Ne+:2.0E+8) is generated.10 bunches are stacked on a same bucket. This process is repeated 10 times with 10ms interval for beam cooling.Finally, Ne+:2E+10 is obtained.
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Baseline
Alternative
TI P
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2429-30 October 2008
ERLERL(Energy Recovery Linac) is employed as the dedicated electron driver.─ 0.48nC, 18.5ns (54MHz) ~ 26mA, E=1.8GeV─ Nγ=2.3E+9 by 0.6 Jx5 CP, Ne+=2.0E+7
By a semi-CW operation (50ms), 1000 times stacking in DR is performed and Ne+=2.0E+10 is obtained.
I ntroduction
Baseline
Alternative
TI P
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2529-30 October 2008
Pulse Stacking Optical Cavity
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2629-30 October 2008
Pulsed Laser Injected CavityR. Chiche
I ntroduction
Baseline
Alternative
TI P
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2729-30 October 2008
High power ps fiber amplifier E. Cormier
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2829-30 October 2008
Experiment at KEK-ATF
Electron beamCSI
γray
e beam
PD
16~28MeV420mm
Collision angle 12 degree
λ:1064nm 10W=28nJ , 2.8ns spacing Pulse length : 7ps
= 30 μm
Mode lock laser
Finess = 780γ/
colli
son
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 2929-30 October 2008
Stacking Simulation
# of positron by a single collision is not sufficient -> need stacking.Stacking simulation in DR (multi-turn injection) shows 10.6% of injected e+ are lost! stacking efficiency ~90%.The tolerance of the injection loss would be qualified.
F. ZimmermannI ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3029-30 October 2008
CLIC Compton Scheme
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Baseline
Alternative
TDP
Summary
Collaboration on Positron Generation strongly supported by CLIC and ILC managements (J.P. Delahaye@PosiPol08)
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3129-30 October 2008
PosiPol-Collaboration
Laser-Compton has a large potential as a future technology. Many common efforts can be shared in a context of various applications.─ X-ray/SR sources for industrial and medical
applications,─ Beam diagnostics with Laser,─ Polarized Positron Generation for ILC, CLIC,
SuperB, ..State-of-the-art technologies are quickly evolved with world-wide synergy.PosiPol collaboration has been started in 2006. The last annual meeting was held at Hiroshima in July 08. The next meeting will be held at near CERN in 2009.
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3229-30 October 2008
WWW of PosiPol R&Ds
Laser Compton
Optical Cavity
High powerlaser
X-raysource
e- sourceILC, ERL
Medicalapplications
Industrialapplications
ERL/Ring4th Generationlight source
LW monitor/Polarimetry
ILC e+
CLIC e+
SuperB
e+source
MaterialScienceScientific
Application
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Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3329-30 October 2008
Minimum machine studiesRe-baseline in 2010(publish in interim report)
Minimum machine studiesRe-baseline in 2010(publish in interim report)
TDP is a multi-phase approach towards TDR.TDP-1 is focused on
Risk mitigationCost reduction
TDP-2 is a real technical design phase based on the design established on TDP-1.
Technical Design Phase
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3429-30 October 2008
ILC Positron Source:MMUndulator is moved to the end of ML (250GeV).─ Energy scan <100GeV is difficult.─ Dedicated pulse for e+ generation with ½L.
QWT instead of AMD, which has lower capture efficiency; The undulator length is 350m.KAS share the common target with gamma1 source; yield is only 1% of the nominal intensity.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3529-30 October 2008
Further Considerations on MMImproved Low P parameter : half # of bunches
in a pulse. It is a big fair wind for the electron driven.─ Potential target damage, which is the most serious
issue on electron driven scheme, is relaxed.─ There are active R&D on noble ideas.
No doubts that Conventional is really “conventional”.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3629-30 October 2008
TDP SummaryBasic R&D is very important in TDP1.Re-baseline at the end of TDP-1 is the mile-stone.According to the investigation based on the latest technology, the status is:
The conventional method is important as a fall-back. Low P parameter and noble target technologies make it feasible and reliable. Technical difficulty forces the undulator system bigger and bigger and it does not seem “mimimal machine”. From the pure technical point of view, the baseline is the electron driven and undulator and laser compton are upgrade alternatives.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3729-30 October 2008
SummaryR&D status of ILC positron source is reviewed.Undulator scheme is the baseline design.─ SC helical Undulator, rotating rim target prototype. ─ Need study for matching device.
e- driven scheme is important as a backup.─ There are several active R&Ds based on noble
ideas. It is the best scheme for MM.
Laser Compton is an advanced alternative. ─ Aggressive R&D efforts. ─ Still need more technical maturity. ─ ILC-CLIC collaboration.
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3829-30 October 2008
Thank you for your attention.
귀하의 관심을 주셔서 감사합니다
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 3929-30 October 2008
TDP-2
TDP-2:-Technical requirements documentation-Technical design work cost update-Value Engineering-Cost & Schedule-18 month period
TDP-2:-Technical requirements documentation-Technical design work cost update-Value Engineering-Cost & Schedule-18 month period
ASIA ILC R&D seminarKympok National University, Taegu, Korea 4029-30 October 2008
Liquid Pb-Sn TargetLiquid Pb target + BN window is very strong against high peak power, but less average power.
Pulsed operation (e.g. 100 bunches with 6.2ns spacing, 0.6μs, 150Hz) moderates thermal effects.
In the pulse operation, capture efficiency is higher and incident electron can be fewer.
P. Logachov et al. in APAC2007
Energy/100ps GeV/mm21012
A
vera
ge p
ower
(kW
)
Operation point
ASIA ILC R&D seminarKympok National University, Taegu, Korea 4129-30 October 2008
RDR Source Layout
Ti-alloy fast rotating target for gamma -> e+ conversion.Capture devices : AMD or QWT + L-band NC accelerator with solenoid focusing.Backup source (500MeV e-, 10% intensity).
I ntroduction
Baseline
Alternative
TDP
Summary
ASIA ILC R&D seminarKympok National University, Taegu, Korea 4229-30 October 2008
Flux Concentrator for KEB upgrade
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Baseline
Alternative
TI P
Summary
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