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POSIPOL workshop 2010. A brief overview. L. Rinolfi. Short history. POSI TONS POL ARISÉS. April 2006. (in French). - PowerPoint PPT Presentation
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C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
POSIPOL workshop 2010
L. Rinolfi
A brief overview
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
POSIPOL is a series of workshops dealing with the physics aspects, the design issues, and the open questions concerning polarized positron sources in the framework of the ILC and CLIC projects. POSIPOL 2010 was the fifth workshop following:
POSIPOL 2006 at CERN Chair: L. RinolfiPOSIPOL 2007 at LAL-Orsay Chair: A. VariolaPOSIPOL 2008 at Hiroshima Chair: M. KurikiPOSIPOL 2009 at IPNL-Lyon Chair: X. ArtruPOSIPOL 2010 at KEK Chair: T. Omori
Short history
POSITONS POLARISÉS
(in French)
April 2006
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
Participants POSIPOL 2010
44 participants (4 from CERN):
M. Petrarca, L. Rinolfi, A. Vivoli, F. Zimmermann
19 Institutes (from America, Asia, Europe):
ANL, BINP, BNL, CERN, DESY, Hiroshima University, IHEP, IPNL/IN2P3, INFN, ISIR, JAEA, KEK, LAL, LLNL, NSC/KIPT, RISE, Tokyo University, Tomsk, Waseda University.
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
Scope of the workshop
POSIPOL 201031/May-2/June, KEK, Tsukuba
T. Omori
POSIPOL 2010 focuses, as in the previous years, on polarized positron sources for ILC and CLIC via Laser-Compton and via undulator-radiation, but also extends topics as target discussions particularly relevant for the conventional positron sources.
For these later, various solid and liquid target materials and pseudo-conventional using channeling are topics of the workshop. POSIPOL 2010 deals also with various high intensity positron sources for other future collider projects, such as B-factories and LHeC.
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
Japan Proton AcceleratorResearch Complex : J-PARC
Mt. Fuji
NaritaTokyo
Kamioka TokaiTsukuba
ee--/e/e++ Collider ColliderB-FactoryB-Factory
Photon-Factory
ILC-Test Facility
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
• The JAHEP community’s master plan• Highest priority is given to ILC• Before ILC, promote flavor physics at KEKB and J-
PARC
• Action before the ILC approval• ILC R&D• Completion/commissioning and continuous
improvements of J-PARC• Upgrade of KEKB/Belle• Collaboration in LHC/ATLAS
Koichiro Nishikawa
News from IPNS director
IPNS = Institute of Particle and Nuclear Study
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23th July 2010CLIC meeting L. Rinolfi
Physics: (1 talk)
Status of e+ sources for colliders :(4 talks: ILC, CLIC, KEKB, BEPC)
ILC-CLIC working group : (1 talk)
Hybrid and channeling e+ sources (CLIC&ILC): (7 talks)
Compton-based e+ sources for colliders (ILC&CLIC):(10 talks)
Undulator-based e+ source for ILC:(4 talks)
Compton-based X-ray and gamma-ray sources : (4 talks)
(including applications to material physics)
Liquid Pb and Pure Conventional e+ sources (ILC): (3 talks)
What was discussed
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23th July 2010CLIC meeting L. Rinolfi
Why polarized e- and e+ beams ?
G. Moortgat-Pick
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23th July 2010CLIC meeting L. Rinolfi
LC Strategy G. Moortgat-Pick
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23th July 2010CLIC meeting L. Rinolfi
Arguments for polarized e+
G. Moortgat-Pick
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
•Undulator •Located at 150GeV point in electron linac•Helical•Pitch = 1.15cm, B=0.86T (K=0.92)•Beam aperture 5.85mm
•Target•Ti Alloy•Wheel with radius 1m, thickness 1.4cm•Rotating speed 100m/s (2000rpm)
•Capture •Flux concentrator
•KAS (Keep Alive Source)•Independent, conventional•10% intensity
ILC - RDR designKaoru Yokoya
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
1) Replace flux concentrator with QWT. Accordingly, undulator length 147m231m to compensate for the less efficient capture.. This does not mean QWT+231m undulator is less risky than FC+147m undulator
(Just because feasibility demonstration of FC is more costly). Higher target load due to longer undulator (x 1.6)
2) Move undulator to linac end •One MPS•Shorter positron transport•No deceleration needed•Everything dirty is concentrated near the center of the complex (BDS,
DR, injectors)
3) Keep Alive Source (~10% intensity) replaced by Auxiliary Source (few % intensity) which shares the target, capture system, etc with the undulator source
Kaoru Yokoya
ILC - SB2009 DesignNot yet the baseline
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23th July 2010CLIC meeting L. Rinolfi
e-/Target Pre-injector
e+ Linac200 MeV
Primary e- Beam Linac5 GeV
Inje
ctor
Lin
ac
2.66
GeV
e+ PDR
2 GHz 2 GHz
2.86 GeV
e
Target
AMD
unpolarized e+
Bunching system
Thermionic e- gun
4.6x109 e+ / bunch
Energy 2.86 GeV
Positron yield (e+/e-) 0.7
Charge 7x109 e+/bunch
Normalized rms emittances 7300 mm.mrad
Energy spread (rms) 113 MeV
Bunch length (rms) 5.3 mm
Longitudinal rms emittance 0.55 m.MeV
polarized e-
CLIC - CDR Design - 3 TeV
at PDR injection
Primary e- beam energy
5 GeV
Number e- / bunch 1010
Source of photons W crystal (1.4 mm)
Target for e+ production
W Amorphous target (10 mm)
Target material (thickness)
W (3 o)
Magnetic field capture system
AMD (6 to 0.5 T)
RF capture system 10 MV/m
at Source
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23th July 2010CLIC meeting L. Rinolfi
SuperKEKB e+ source upgrade
T. Kamitani
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T. Kamitani
Status of SuperB factories
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23th July 2010CLIC meeting L. Rinolfi
Parameters Design Test results BEPC
Energy ( GeV) 1.89 1.89 1.30-1.55
Current (mA) e+ 37 66 ~5
e- 500 550 300
Emittance ( 1σ, mm-mrad)
e+ 0.40 0.35 ~ 0.27 ----
e- 0.10 0.097~0.079 ----
Energy spread (1σ, %)
e+ 0.50 0.371 ~0.80
e- 0.50 0.295 ~0.80
Energy stability ( % )
0.15 0.05 ----
Orbit stability (mm)
0.30 0.119 ~0.058 ----
Repetition rate 50 50 12.5
e+ injection rate( mA / min.)
50 61.5 1 ~ 3
Status of BEPC IIG. PeiImpressive progress from BEPC to BEPC II at Beijing
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23th July 2010CLIC meeting L. Rinolfi
Institutes: 5 from Asia, 6 from USA and 9 from Europe
A review of the milestones will be done at the coming LC workshop in October 2010 at Geneva.
R&D plan for e+ studies “ILC-CLIC e+ generation” working group
Important reduction of resources have registered in several institutes.
Therefore the ILC/CLIC work plan is reviewed according to the available resources from the different institutes around the world and the
possible contributions are presented.
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23th July 2010CLIC meeting L. Rinolfi
S. Dabagov
Channeling of charged particles
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23th July 2010CLIC meeting L. Rinolfi
Simulations for hybrid sources
Crystal target
Amorphous target
e- Photons
e+
O. Dadoun
=> will be included into G4and X. Artru simulation
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23th July 2010CLIC meeting L. Rinolfi
Channeling simulations
O. DadounComparison of 2 codes
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23th July 2010CLIC meeting L. Rinolfi
• CLIC: incident beam: 5 Gev; t1=1.4 mm; t2=10 mm
• ACCEPTED POSITRON YIELD• * For an incident e- beam with = 1 mm => 1 e+/e-• * For an incident e- beam with = 2.5 mm => = 0.9 e+/e-
• PEDD (Peak Energy Deposition Density) • Assuming an incident e- pulse of 2.34 1012 e-, we have :• CRYSTAL AMORPHOUS• PEDD/e- PEDD/total PEDD/e- PEDD/total• (GeV/cm3/e-) J/g (GeV/cm3/e-) J/g
mm 2 38 2.5 48.5 =2.5mm 0.35 6.8 0.8 15.5
• An entirely amorphous target, 9 mm thick, with the same incident e- beam would have provided the same accepted yield and a PEDD of 150 J/g (=1mm) or 40J/g (=2.5 mm). This shows the advantages of an hybrid scheme leading to a unique target with a PEDD < 35 J/g using an e- beam with = 2.5 mm.
Hybrid source advantage R. Chehab
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23th July 2010CLIC meeting L. Rinolfi
S
cm
N. e+
Yield
e+/e-
x mm mrad
y
mm mrad
<E> MeV
E
MeV
z
mm
z
cm MeV
4348 4204 0.70 7685 8105 2825.4 126.3 5.4 61.6
e+ in PDR: 2720; Yield e+/e- =0.453
A. Vivoli
CLIC Injector Linac
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Set up SiteLooking up from Down stream
KEKB Linac Tests for e+ production from hybrid targets
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Zoom on e+ crystal target
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23th July 2010CLIC meeting L. Rinolfi
hybrid
on axishybrid
off axis
conventional
8mm
conventional
18mm
3.4 enhancement
e+ yield (ADC counts)
black: 1mm W crystal
+ 8mm W amorphous
e+ yield at KEKB LinacExperimental results from hybrid targets T. Takahashi
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23th July 2010CLIC meeting L. Rinolfi
Why Compton scheme ?
1) Method to obtain polarized e+ (up to 90%)
2) Dedicated low energy e- beam (no inter-system dependence)
3) No issue for low energy scan operation
4) Technology feasibility can be evaluated before final construction
BUT still some difficulties:
1) Laser ( high power and high quality)
2) Optical cavity
3) Electrons: Ring-based, ERL-based, Linac-based Compton scheme
4) Positron stacking required
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Optimal Compton ringE. Bulyak
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F. Zomer
Optical cavity with 4 mirrors
For polarized e+ Compton source at ATF/KEK
Cavity arrived yesterday at Narita
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23th July 2010CLIC meeting L. Rinolfi
I. Chaikovska
Compton with multiple IP
Characteristics for simulations of polarized gammas source
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23th July 2010CLIC meeting L. Rinolfi
I. Chaikovska
Results for e+ production
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23th July 2010CLIC meeting L. Rinolfi
SR 1 47 m
e+ PDR
ERL32 ns
50 Hz
400 m
25 Hz
0.5 ns
312 bunches / train
1 train / ring
312 bunches spaced by 0.5 ns => 155.5 ns / turn
Stack in the same bucket every 69th turn
Number of stacking in the same bucket 1864
69 x 1864 = 128 617 turns
128 617 x 155.5 ns = 20 ms
SR 2 47 m
new CLIC scheme
Based on 2 CLIC stacking rings option F. Zimmermann
e+ stacking simulations
CLIC stacking rings must have much shorter damping times ~50 s and higher RF voltage (35 MV) than SLC damping rings
Large off-momentum dynamic aperture up to inj~9% (!) is also required
Preliminary simulations with semi-optimized parameters indicate >95% stacking efficiency
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
Linac-based Compton scheme
Conventional Non-Polarized Positrons:
3-atmCO2 amplifier
parabolic mirrors
vacuum cell
detector
YAG (14 ps)200 ns
200 ps
Ge
3% over 1 s
First tests of the laser cavity:
Polarized -ray beam is generated in the Compton back scattering inside optical cavity of CO2 laser beam and 6 GeV e-beam produced by linac.
Laser cavity needs R&D.
6GeV e- beam 60MeV
beam 30MeV
e+ beam
to e+ conv. target
~2 m
V. Yakimenko
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23th July 2010CLIC meeting L. Rinolfi
ILC CLIC SuperB
Required e+/sec 3 1014 1.2 1014 3.2 1011
Required beam format 2856@5Hz 354@50Hz
1600@5min
Source beam format 286@50Hz 50@50Hz
Required e+ /bunch 3nC/2 1010 1nC/6 109 20pC/1.2 108
e- beam energy 6 – 4 GeV
beam peak energy 60 - 30 MeV
Ne+/N capture 2% (4%)
e- bunch charge 15(7.5)nC 5nC 1nC
bunch length (laser&e- beams)
3 ps
Number of laser IPS 10 10(5) 1
Total N/Ne- yield (in all IPs) 10 10(5) 1
Ne+/Ne- yield 0.2 0.2 0.02
# of stacking No stacking
V. Yakimenko
Compton Linac e+ sources
Proposed parameters are in black, Optimistic numbers are in Red
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
•There is no funding for ATF to work directly for ILC, CLIC or SuperB:
•development of CO2 regenerative cavity, •high repetition rate operations
•There is an active program to use highest Compton X ray peak flux for single shot user experiments:
•Started with High efficiency conversion ~1x ray / 1 electron, Spatial distribution of second harmonic (U. Tokyo, KEK)
•Phase contrast imaging (INFN)•Diffraction scattering on the crystal (UCLA)
•There is an active CO2 development program at ATF
•required for ILC pulse parameters and amplifier bandwidth is demonstrated
•Gradual increase of the single pulse intensity is the main goal.
V. Yakimenko
Summary from BNL
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
1) Higher harmonics are important and can influence the overall polarization.
2) Polarization and yields are always conflicting, compromises need to be made.
3) Lower energy drive beam (150 GeV) is more practical in achieving high degree polarization than higher drive beam energy (250 GeV).
W. Gai
Summary from ANL
Polarization issues with undulator based e+ source
Undulator 100 m long and drive beam energy 150 GeV
Collimator distance = 700 m Collimator iris = 2.5 mm
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23th July 2010CLIC meeting L. Rinolfi
Shock wave on BN windowT. OmoriExperiment performed at KEKB
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23th July 2010CLIC meeting L. Rinolfi
Summary from KEKT. Omori
C L I CC L I C
23th July 2010CLIC meeting L. Rinolfi
1) Review e+ sources of colliders
2) “ILC-CLIC e+ generation” working group Set new milestones
3) Hybrid and channeling e+ sources Review design progress for CLIC baseline source Review R&D status and set next goals
4) Compton Review R&D status and design progress Review the industrial, medical, material applications
5) Undulator Review R&D status and design progress Prepare re-baseline for ILC baseline source
6) Liquid Pb and Pure Conventional e+ sources Review R&D status and set next goals
Workshop achievements
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23th July 2010CLIC meeting L. Rinolfi
ILC NewsLine Report
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23th July 2010CLIC meeting L. Rinolfi
Apologizes for the talks which have not been mentioned in this Summary
http://atfweb.kek.jp/posipol/2010/index.htmlAll talks from the following link:
POSIPOL 2011
POSIPOL 2012 at Hamburg hosted by DESY
Conclusion
at Beijing hosted by IHEP