1. Compton Ring/ERL e+ Source
for ILC/CLIC
Tsunehiko OMORI (KEK)
Compton Source for X/gamma Rays
12-Sep Sardinia, Italy

2. Today's Talk Two Energy Frontier Machines LHC and a Linear Collider
2. Why Liner Collider
3. Why Beam Polarization
4. Why Laser-Compton for ILC/CLIC e+ Source
5. Ring/ERL Compton e+ Source
6. R/Ds and PosiPol Collaboration
7. Summary

3. Energy Frontier Machines
Two
Energy Frontier Machines

4. LHC Large Hadron Collider
Energy Frontier Machines
LHC Large Hadron Collider
ILC Liner Collider
Central Campus
Main Linac Tunnel
CERN
pp collider
Detector Hall
Circumference = 27 km
e- e+ collider
L = km
Tunnel and Facility
Superconducting
Magnets
Superconducting
RF Accelerating Module
ATLAS detector
40m x 40 m x 40 m 4 4

5. LHC Large Hadron Collider
Energy Frontier Machines
LHC Large Hadron Collider
ILC Liner Collider
First Beam Sep 10th!
Central Campus
Main Linac Tunnel
CERN
pp collider
Detector Hall
Circumference = 27 km
e- e+ collider
L = km
Tunnel and Facility
Superconducting
Magnets
Superconducting
RF Accelerating Module
ATLAS detector
40m x 40 m x 40 m 5 5

6. Why Linear Collider

7. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced) p p
e-e+ collider (ILC/CLIC) e- e+

8. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced) p p
e-e+ collider (ILC/CLIC) e- e+

9. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced) p p
e-e+ collider (ILC/CLIC) e- e+

10. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced)
Small back ground
Mostly full reconstruction p p
e-e+ collider (ILC/CLIC) e- e+

11. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced)
Small back ground
Mostly full reconstruction p p
e-e+ collider (ILC/CLIC) e- e+
Precision data
Reconstruct laws of physics

12. Why we need e-e+ collider ?
pp collider (LHC)
e-e+ : elementary particles
CMS energy = 2 x beam energy
(well defined)
Total momentum = 0 (balanced)
Small back ground
Mostly full reconstruction p p
e-e+ collider (ILC/CLIC)
Beam polarization e- e+
pol.
pol.
Why polarized beams?

13. Why Beam Polarization?

14. R-hand electron (e-R) and L-hand electron (e-L)
Spin e- R
Momentum e- L

15. e- R e- L R-hand electron (e-R) and L-hand electron (e-L)
are different particles in high energy
Spin e- R NO
Weak Interaction
e-R
Momentum
e-L nL e- L
Weak Interaction

16. e- R e- L e+ R e+ L R-hand electron (e-R) and L-hand electron (e-L)
are different particles in high energy
Spin e- R NO
Weak Interaction
e-R
Momentum
e-L nL e- L
Weak Interaction
R-hand positron (e+R) and L-hand positron (e+L)
are different particles in high energy
Spin
e+R nR e+ R
Weak Interaction
Momentum e+ L
e+L NO
Weak Interaction

17. Example : Scaler mR search (Min. SUSY)~
Signal e- c0 ~
(invisible) m+
m+R ~ e+ c0 ~
(invisible)

18. Example : Scaler mR search (Min. SUSY)~
Signal e- c0 ~
(invisible) m+
m+R ~ e+ c0 ~
(invisible)
Background : W- W+ pair m- e- W- n
(invisible) n m+ e+ W+ n
(invisible) m- e- W- n
(invisible) W3 m+ e+ W+ n
(invisible)

19. Example : Scaler mR search (Min. SUSY)
Monte Carlo Sim.
non pol.
W-W+ ~ ~
m-Rm+R

20. Example : Scaler mR search (Min. SUSY)~
Signal
e-R c0 ~
(invisible) m+
m+R ~
e+L c0 ~
(invisible)
Background : W- W+ pair m-
e-R W- n
(invisible) nR m+
e+L W+ n
(invisible) m-
e-R W- n
(invisible) W3 m+
e+L W+ n
(invisible)

21. Example : Scaler mR search (Min. SUSY)~
Signal
e-R c0 ~
(invisible) m+
m+R ~
e+L c0 ~
(invisible)
Background : W- W+ pair m-
e-R W- NO n
(invisible) nR m+
e+L W+ n
(invisible) m-
e-R W- NO n
(invisible) W3 m+
e+L W+ n
(invisible)

22. Example : Scaler mR search (Min. SUSY)~
Signal
e-R c0 ~
(invisible) m+
m+R ~
e+L c0 ~
Coupling
(invisible)
e+R
e-L
Y = -1/2 s = 1
e+L
e-R
Larger
Y = s = 4
Background : W- W+ pair m-
e-R W- NO n
(invisible) nR m+
e+L W+ n
(invisible) m-
e-R W- NO n
(invisible) W3 m+
e+L W+ n
(invisible)

23. Example : Scaler mR search (Min. SUSY)
Monte Carlo Sim.
non pol.
pol e- = 80%(R) pol e+ = 60%(L)
W-W+ ~ ~ ~ ~
m-Rm+R
m-Rm+R
W-W+

24. Why polarized beams ? e-R and e-L are different particles nL e-R e-L
(A) In high energy,
e-R and e-L are different particles
e-L nL NO
Weak Interaction
e-R
Weak Interaction
e+R and e+L are different particles
e+R nR NO
Weak Interaction
e+L
Weak Interaction
(B) Chose initial state (e-Re+L , e-Le+R, ....)
(1) Suppress background (esp. e-e+ -> W-W+)
(2) Enhance specific int.
(3) Control angular dist. of final state
(4) Determine weak mix of the final
(5) Reduce sys. errors
(6) Study why nature chose (A) (hint neutrino osc.)

25. Why Laser-Compton
for ILC/CLIC e+ source

26. Two ways to get pol. e+ (1) Helical Undurator (2) Laser Compton
e- beam
E >150 GeV
Undulator
L > 200 m
(2) Laser Compton

27. Two ways to get pol. e+ (1) Helical Undurator (2) Laser Compton
e- beam
E >150 GeV
Undulator
L > 200 m
Our Proposal
(2) Laser Compton

28. Why Laser-Compton ? i) Positron Polarization. ii) Independence
Undulator-base e+ : use e- main linac
Problem on design, construction,
commissioning, maintenance,
Laser-base e : independent
Easier construction, operation,
commissioning, maintenance

29. ILC Undulator-base e+ Source
150 GeV
250 GeV
250 GeV
Experiments

30. Why Laser-Compton ? i) Positron Polarization. ii) Independence
Undulator-base e+ : use e- main linac
Problem on design, construction,
commissioning, maintenance,
Laser-base e : independent
Easier construction, operation,
commissioning, maintenance

31. Why Laser-Compton ? i) Positron Polarization. ii) Independence
Undulator-base e+ : use e- main linac
Problem on design, construction,
commissioning, maintenance,
Laser-base e : independent
Easier construction, operation,
commissioning, maintenance
iii) Polarization 5Hz (for 50 Hz)
iv) High polarization
v) Low energy operation
Undulator-base e+ : need deceleration
Laser-base e+ : no problem

32. Why Laser-Compton ? i) Positron Polarization. ii) Independence
Undulator-base e+ : use e- main linac
Problem on design, construction,
commissioning, maintenance,
Laser-base e : independent
Easier construction, operation,
commissioning, maintenance
iii) Polarization 5Hz (for 50 Hz)
iv) High polarization
v) Low energy operation
Undulator-base e+ : need deceleration
Laser-base e+ : no problem
vi) Synergy in wide area of fields/applications

33. Status of Compton e+ Source
Proof-of-Principle demonstration was done.
ATF-Compton Collaboration
Polarized -ray generation: M. Fukuda et al., PRL 91(2003)164801
Polarized e+ generation: T. Omori et al., PRL 96 (2006)

34. Status of Compton e+ Source
Proof-of-Principle demonstration was done.
ATF-Compton Collaboration
Polarized -ray generation: M. Fukuda et al., PRL 91(2003)164801
Polarized e+ generation: T. Omori et al., PRL 96 (2006)

35. Asymmetry Measurements
e+ run
A = 0.90 ± 0.18 %
T. Omori et al., PRL 96 (2006)
T. Omori et al., PRL 96 (2006)

36. Asymmetry Measurements
e+ run
e- run
A = 0.90 ± 0.18 %
A = 0.89 ± 0.19 %
T. Omori et al., PRL 96 (2006)
T. Omori et al., PRL 96 (2006)

37. Status of Compton e+ Source
Proof-of-Principle demonstration was done.
ATF-Compton Collaboration
Polarized -ray generation: M. Fukuda et al., PRL 91(2003)164801
Polarized e+ generation: T. Omori et al., PRL 96 (2006)
We still need many R/Ds and simulations.
We heard many talks in this WS

38. Status of Compton e+ Source
Proof-of-Principle demonstration was done.
ATF-Compton Collaboration
Polarized -ray generation: M. Fukuda et al., PRL 91(2003)164801
Polarized e+ generation: T. Omori et al., PRL 96 (2006)
We still need many R/Ds and simulations.
We heard many talks in this WS
We have 3 schemes.
Choice 1 : How to provide e- beam
Storage Ring, ERL, Linac
Choice 2 : How to provide laser beam
Wave length (=1m or =10m )
staking cavity or non stacking cavity
Choice 3 : e+ stacking in DR or Not

39. Laser Compton e+ Source for ILC/CLIC
We have 3 schemes.
1. Ring Base Laser Compton
Storage Ring + Laser Stacking Cavity (=1m),
and e+ stacking in DR
S. Araki et al., physics/
2. ERL Base Laser Compton
ERL + Laser Stacking Cavity (=1m),
and e+ stacking in DR
3. Linac Base Laser Compton
Linac + non-stacking Laser Cavity (=10m),
and No stacking in DR
Proposal V. Yakimenko and I. Pogorersky
T. Omori et al., Nucl. Instr. and Meth. in Phys. Res., A500 (2003) pp
Good! But we have to choose!

40. Laser Compton e+ Source for ILC/CLIC
We have 3 schemes.
1. Ring Base Laser Compton
Storage Ring + Laser Stacking Cavity (=1m),
and e+ stacking in DR
S. Araki et al., physics/
2. ERL Base Laser Compton
ERL + Laser Stacking Cavity (=1m),
and e+ stacking in DR
3. Linac Base Laser Compton
Linac + non-stacking Laser Cavity (=10m),
and No stacking in DR
Vitaly's talk today
Proposal V. Yakimenko and I. Pogorersky
T. Omori et al., Nucl. Instr. and Meth. in Phys. Res., A500 (2003) pp
Good! But we have to choose!

41. Laser Compton e+ Source for ILC/CLIC
We have 3 schemes.
1. Ring Base Laser Compton
Storage Ring + Laser Stacking Cavity (=1m),
and e+ stacking in DR
Variola's talk on 11th
S. Araki et al., physics/
2. ERL Base Laser Compton
ERL + Laser Stacking Cavity (=1m),
and e+ stacking in DR
Variola's talk on 11th
3. Linac Base Laser Compton
Linac + non-stacking Laser Cavity (=10m),
and No stacking in DR
Vitaly's talk today
Proposal V. Yakimenko and I. Pogorersky
T. Omori et al., Nucl. Instr. and Meth. in Phys. Res., A500 (2003) pp
Good! But we have to choose!

42. Laser Compton e+ Source for ILC/CLIC
We have 3 schemes.
My talk today
1. Ring Base Laser Compton
Storage Ring + Laser Stacking Cavity (=1m),
and e+ stacking in DR
Variola's talk on 11th
S. Araki et al., physics/
2. ERL Base Laser Compton
ERL + Laser Stacking Cavity (=1m),
and e+ stacking in DR
Variola's talk on 11th
3. Linac Base Laser Compton
Linac + non-stacking Laser Cavity (=10m),
and No stacking in DR
Vitaly's talk today
Proposal V. Yakimenko and I. Pogorersky
T. Omori et al., Nucl. Instr. and Meth. in Phys. Res., A500 (2003) pp
Good! But we have to choose!

43. Ring/ERL
Compton Scheme

44. Ring Base Compton (an example)
Re-use Concept
laser pulse stacking optical cavities
Re-use photon beam
positron stacking in main DR
Electron storage ring
(or ERL)
Re-use electron beam
to main linac

45. Compton Ring Scheme for ILC
Compton scattering of e- beam stored in storage ring off laser stored in Optical Cavity.
5.3 nC 1.8 GeV electron bunches x 5 of 600mJ stored laser -> 2.3E+10 γ rays -> 2.0E+8 e+.
By stacking 100 bunches on a same bucket in DR, 2.0E+10 e+/bunch is obtained.
Electron Storage Ring 1.8 GeV
1.8 GeV booster
preliminary

46. ERL scheme for ILC 1000 times of stacking in a same bunch
High yield + high repetition in ERL solution.
0.48 nC 1.8 GeV bunches x 5 of 600 mJ laser, repeated by 54 MHz -> 2.5E+9 γ-rays -> 2E+7 e+.
Continuous stacking the e+ bunches on a same bucket in DR during 100ms, the final intensity is 2E+10 e+.
1000 times of stacking in a same bunch
SC Linac 1.8 GeV
Laser Optical Cavities
Photon
Conversion
Target
Capture
System
To Positron
Liniac
RF Gun
Dump
preliminary

47. Ring scheme and ERL scheme are SIMILAR
Electron Storage Ring 1.8 GeV
1.8 GeV booster
Ring Scheme
SC Linac 1.8 GeV
Laser Optical Cavities
Photon
Conversion
Target
Capture
System
To Positron
Liniac
RF Gun
Dump
ERL scheme

48. Compton Ring scheme for CLIC (2008)
Compton configuration for polarized e+
2.424 GeV
e+ DR
2.424 GeV
460 turns makes 312 bunches with 6.4x109 e+/bunch
e+ PDR and Accumulator ring
C = 47 m, 156 ns/turn, 312 bunches with 6.2x1010 e-/bunch
Injector Linac
2.2 GeV
2 GHz
RF gun
Drive Linac
1.3 GeV
2 GHz
Compton ring
2 GHz
50 Hz
Pre-injector
Linac for e+
200 MeV g
Stacking cavity
g (23-29 MeV) 7x108 /turn/bunch
1.4x107 pol. e+/turn/bunch
e+ target
F. Zimmermann & L. Rinolfi
1 YAG Laser pulse

49. PosiPol Collaboration
R/Ds
and
PosiPol Collaboration

50. R&D items Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CR/ERL simulations studies (Kharkov, LAL, JAEA, KEK)
design studies
beam dynamics studies
Urakawa-san's talk 11th
Optical Cavity (LAL, Hiroshima, KEK)
Variola-san's talk 11th
experimental R/D
Fabian-san's talk 10th
e+ capture (LAL, ANL)
We will start collaboration with KEKB upgrade study
e+ stacking in DR (CERN)
Basic beam dynamics studies
Laser
Fabian-san's talk 11th
Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CO2 laser (BNL)
Vitaly-san's
talk today

51. World-wide PosiPol Collaboration
Collaborating Institutes:
BINP, CERN, DESY, Hiroshima, IHEP, IPN, KEK,
Kyoto, LAL, CELIA/Bordeaux, NIRS, NSC-KIPT,
SHI, Waseda, BNL, JAEA and ANL
Sakae Araki, Yasuo Higashi, Yousuke Honda, Masao Kuriki, Toshiyuki Okugi, Tsunehiko Omori,
Takashi Taniguchi, Nobuhiro Terunuma, Junji Urakawa, Yoshimasa Kurihara, Takuya Kamitani,
Yoshisato Funahashi, X. Artru, M. Chevallier, V. Strakhovenko, Eugene Bulyak, Peter Gladkikh,
Klaus Meonig, Robert Chehab, Alessandro Variola, Fabian Zomer, Alessandro Vivoli, Richard Cizeron,
Viktor Soskov, Didier Jehanno, M. Jacquet, R. Chiche, Yasmina Federa, Eric Cormier,
Louis Rinolfi, Frank Zimmermann, Kazuyuki Sakaue, Tachishige Hirose, Masakazu Washio,
Noboru Sasao, Hirokazu Yokoyama, Masafumi Fukuda, Koichiro Hirano, Mikio Takano,
Tohru Takahashi, Hirotaka Shimizu, Shuhei Miyoshi, Yasuaki Ushio, Tomoya Akagi, Akira Tsunemi,
Ryoichi Hajima, Li XaioPing, Pei Guoxi, Jie Gao, V. Yakinenko, Igo Pogorelsky, Wai Gai, and Wanming Liu
POSIPOL 2006
CERN Geneve
26-27 April
POSIPOL 2008
Hiroshima
16-18 June
POSIPOL 2007
LAL Orsay
23-25 May

52. World-wide PosiPol Collaboration
Collaborating Institutes:
BINP, CERN, DESY, Hiroshima, IHEP, IPN, KEK,
Kyoto, LAL, CELIA/Bordeaux, NIRS, NSC-KIPT,
SHI, Waseda, BNL, JAEA and ANL
Sakae Araki, Yasuo Higashi, Yousuke Honda, Masao Kuriki, Toshiyuki Okugi, Tsunehiko Omori,
Takashi Taniguchi, Nobuhiro Terunuma, Junji Urakawa, Yoshimasa Kurihara, Takuya Kamitani,
Yoshisato Funahashi, X. Artru, M. Chevallier, V. Strakhovenko, Eugene Bulyak, Peter Gladkikh,
Klaus Meonig, Robert Chehab, Alessandro Variola, Fabian Zomer, Alessandro Vivoli, Richard Cizeron,
Viktor Soskov, Didier Jehanno, M. Jacquet, R. Chiche, Yasmina Federa, Eric Cormier,
Louis Rinolfi, Frank Zimmermann, Kazuyuki Sakaue, Tachishige Hirose, Masakazu Washio,
Noboru Sasao, Hirokazu Yokoyama, Masafumi Fukuda, Koichiro Hirano, Mikio Takano,
Tohru Takahashi, Hirotaka Shimizu, Shuhei Miyoshi, Yasuaki Ushio, Tomoya Akagi, Akira Tsunemi,
Ryoichi Hajima, Li XaioPing, Pei Guoxi, Jie Gao, V. Yakinenko, Igo Pogorelsky, Wai Gai, and Wanming Liu
POSIPOL 2006
CERN Geneve
26-27 April
POSIPOL 2008
Hiroshima
16-18 June
POSIPOL 2007
LAL Orsay
23-25 May
POSIPOL 2009
CERN/ near CERN

53. R&D items Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CR/ERL simulations studies (Kharkov, LAL, JAEA, KEK)
design studies
beam dynamics studies
Optical Cavity (LAL, Hiroshima, KEK)
experimental R/D
e+ capture (LAL, ANL)
We will start collaboration with KEKB upgrade study
e+ stacking in DR (CERN)
Basic beam dynamics studies
Laser
Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CO2 laser (BNL)

54. R&D items Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CR/ERL simulations studies (Kharkov, LAL, JAEA, KEK)
design studies
beam dynamics studies
Optical Cavity (LAL, Hiroshima, KEK)
experimental R/D
e+ capture (LAL, ANL)
We will start collaboration with KEKB upgrade study
Common in
most of Compton
Applications
e+ stacking in DR (CERN)
Basic beam dynamics studies
Laser
Fiber laser / Mode-lock laser (CELIA/Bordeaux)
CO2 laser (BNL)

55. Optical Super Cavities
Example of
Common R/Ds
Optical Super Cavities
2-mirror cavity
(Hiroshima / Weseda /
Kyoto / IHEP / KEK)
4-mirror cavity (LAL)
moderate enhancement
moderate spot size
simple control
high enhancement
small spot size
complicated control

56. World-Wide-Web of Laser Compton

57. Laser-Compton R/D
1. Laser-Compton has a large potential as a future technology.
2. Many common efforts can be shared in a context of various applications.
– Compact and high quality X-ray source for industrial and medical applications
– -ray source for disposal of nuclear wastes
– Beam diagnostics with Laser
– Laser Cooling
– Polarized Positron Generation for ILC and CLIC
–  collider
3. State-of-the-art technologies are quickly evolved with world- wide synergy.
– Laser Stacking Optical Cavity,
– Laser,
– ERL

58. Summary

59. Summary 1 1. Two Energy Frontier Machines LHC pp collider
Will Open New Era in Particle physics
ILC e-e+ collider
Will follow LHC and provide precision data

60. Summary 1 1. Two Energy Frontier Machines LHC pp collider
Will Open New Era in Particle physics
ILC e-e+ collider
Will follow LHC and provide precision dada
2. Beam polarization plays important roles in e-e+ colliders
Suppress back ground
Enhance specific interaction
Determine Weak mixing of final state

61. Summary 1 1. Two Energy Frontier Machines LHC pp collider
Will Open New Era in Particle physics
ILC e-e+ collider
Will follow LHC and provide precision dada
2. Beam polarization plays important roles in e-e+ colliders
Suppress back ground
Enhance specific interaction
Determine Weak mixing of final state
3. Compton pol. e+ source is attractive option for ILC/CLIC
Independent system
high polarization
5 Hz polarization flip (for CLIC 50 Hz flip)
Operability

62. Summary 2 4. Three schemes are proposed Ring Laser Compton
ERL Laser Compton
Linac Laser Compton

63. Summary 2 4. Three schemes are proposed Ring Laser Compton
ERL Laser Compton
Linac Laser Compton
My talk Today

64. Summary 2 4. Three schemes are proposed 5. We still need many R/Ds
Ring Laser Compton
ERL Laser Compton
Linac Laser Compton
My talk Today
5. We still need many R/Ds
(a) e+ stacking, (b) Ring, (c) ERL, (d) e+ capture
(e) e+ production target, (e) Laser
(g) Laser stacking optical cavity

65. Summary 2 4. Three schemes are proposed
Ring Laser Compton
ERL Laser Compton
Linac Laser Compton
My talk Today
5. We still need many R/Ds ---> Good! We have many funs.
(a) e+ stacking, (b) Ring, (c) ERL, (d) e+ capture
(e) e+ production target, (e) Laser
(g) Laser stacking optical cavity

66. Summary 2 4. Three schemes are proposed
Ring Laser Compton
ERL Laser Compton
Linac Laser Compton
My talk Today
5. We still need many R/Ds ---> Good! We have many funs.
(a) e+ stacking, (b) Ring, (c) ERL, (d) e+ capture
(e) e+ production target, (e) Laser
(g) Laser stacking optical cavity
6. Laser-Compton has many applications in many field.
Medical applications, Industrial applications,
-ray source for disposal of nuclear wastes,
cargo inspections, research of cultural heritages,
and
also for ILC/CLIC e+ source.
Many of R/D are common in most of applications