1. Accelerator R&D Ralph W. Aßmann Leading Scientist, DESY 23.07.2013 Acknowledge discussions with and/or material from: F. Zimmermann, A. Caldwell, N. Walker, A. Seryi, R. Brinkmann, M. Harrison, S. Myers, L. Rossi, M. Klein, O. Brüning, K. Oide, H. Padamse, A. Blondel, D. Schulte, F. Bordry, J. Osterhoff, E. Elsen, F. Grüner, K. Flöttmann, P. Muggli, G. Mourou, B. Holzer, A. Specka, H. Weise, …

2. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 2 Accelerator R&D Starting in Sweden in 1924…

3. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 3 Outline > Acceleration in metallic RF structures > Towards high luminosity > Higgs collider concepts with leptons > “New” ideas and concepts > Conclusion

4. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 4 RF Acceleration in Metallic Structures Courtesy Padamse, Tigner Courtesy N. Walker From Ising’s and Wideröe’s start to 21 st century RF technology.

5. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 5 Different RF Frequencies IEEE Standard 521-1984 http://www.microwaves101.com/ Low frequency  long waves Larger dimensions, lower gradients, lower disturbing wakefields SC RF technology is here Low frequency  long waves Larger dimensions, lower gradients, lower disturbing wakefields SC RF technology is here Technology of SLAC linac (1960’s) Work horse for many accelerators Technology of SLAC linac (1960’s) Work horse for many accelerators Newer RF technology (rising interest) Several new linacs rely on it (Japan, Switzerland, China, ELI?) Newer RF technology (rising interest) Several new linacs rely on it (Japan, Switzerland, China, ELI?) High frequency  short waves Smaller dimensions, higher gradients, higher disturbing WF’s NC linear colliders (NLC, CLIC) High frequency  short waves Smaller dimensions, higher gradients, higher disturbing WF’s NC linear colliders (NLC, CLIC)

6. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 6 X-Band Technology (12 GHz): CLIC P.K. Skowronski et al, IPAC2011

7. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 7 X-Band Technology (12 GHz): CLIC P.K. Skowronski et al, IPAC2011 ≈ 4 × 10 -3 breakdowns per 1 million

8. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 8 If Accelerating Gradients Pushed too High (30 GHz)… W. Wuensch Location of damage Single feed power coupler 30 GHz, 16 ns, 66 MV/m local accelerating gradient W. Wuensch 2002 Major success for X-band: mastering of breakdown problem without damage. Limitation for much higher gradients than 100 MeV/m!

9. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 9 Why the Trend towards Super-Conducting RF?

10. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 10 Production Yield and Even Higher Gradients: ILC > Production quality reaches demands of big projects: > R&D towards much higher accelerating gradients ( not achieved yet ):  Nb3Sn :Tc = 18 K, Hsh = 3000 Oe => E acc = 80 MV/m (improved shape cavity)  MgB2:Tc = 38 K, Hsh = 6200 Oe = > E acc = 172 MV/m (improved shape cavity) ILC accelerating gradient spec: 31.5 MV/m ±20% Exceeds 2005 GDE R&D goal Courtesy N. Walker Padamse, Tigner

11. 50 Yr-Growth of Installed Voltage for v/c=1 Accelerators Year Jlab LEP-II SNS FLASH XFEL Jlab-Upgrade MVolt Courtesy Padamse, Tigner

12. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 12 Outline > Acceleration in metallic RF structures > Towards high luminosity > Higgs collider concepts with leptons > “New” ideas and concepts > Conclusion

13. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 13 Towards Very Small Beam Sizes in LC’s: ATF2 (Japan) as Test Bed for ILC

14. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 14 Achieved Beam Sizes with New Optics Scheme in ATF2 Figure by A. Seryi et al Note: Scanning Transmission Electron Micro- scopes achieve sub-nm spot size! ATF2 goal

15. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 15 SuperKEKB (in construction for beam commissioning in 2015) Will break into new territory for e+e- colliders! nano-beam scheme K. Oide et al

16. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 16 Developments towards High Luminosity

17. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 17 Outline > Acceleration in metallic RF structures > Towards high luminosity > Higgs collider concepts with leptons > “New” ideas and concepts > Conclusion

18. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 18 Known Higgs Boson Energy  e+e- Higgs Factory Design… Some IPAC2013 Papers

19. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 19 epton collider o ptions beyond LHC L epton collider o ptions beyond LHC

20. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 20 epton collider o ptions beyond LHC L epton collider o ptions beyond LHC TDR’s published

21. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 21 epton collider o ptions beyond LHC L epton collider o ptions beyond LHC TDR’s published

22. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 22 epton collider o ptions beyond LHC L epton collider o ptions beyond LHC TDR’s published TDR to be worked out

23. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 23 epton collider o ptions beyond LHC L epton collider o ptions beyond LHC TDR’s published TDR to be worked out

24. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 24 The Large Hadron Electron Collider (LHeC)  Mike L.

25. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 25 e+e-: Linear Collider Baseline and the Circular Version Courtesy F. Zimmermann & K. Oide CLIC ILC TLEP Figure F. Zimmermann & K. Oide

26. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 26 e+e-: Linear Collider and the Circular Version Courtesy F. Zimmermann & K. Oide CLIC ILC TLEP TLEP is 1.15 times LEP2 (1998 – 2001) in terms of energy Tunnel length is 3-4 times LEP/LHC tunnel  luminosity Requires ring injector infrastructure, as existing at CERN Low Higgs mass regenerated interest as Higgs factory e+e- circular collider is strong at lower energies Luminosity drops sharply with energy 4 simultaneous experiments are possible Strong synchrotron radiation damping Beam property fixed by equilibrium (stable but inflexible) Can be superseded by pp collider but not be upgradeable in E ILC is the baseline complementary approach to LHC e+e- linear collider without competition at higher energies Luminosity increases with energy Can operate efficiently beyond the Higgs energy Long. polarization available in collision 1 simultaneous experiment, 2 nd experiment with push-pull High flexibility pulse by pulse Initial Higgs-only stage can be implemented (reduced cost) Upgradeable in E max with higher gradient RF (afterburner)

27. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 27 Required Accelerator R&D for ILC, TLEP, …

28. 500 GeV Parameters Max. E cm 500 GeV Luminosity 1.8×10 34 cm -2 s -1 Polarisation (e-/e+) 80% / 30%  BS 4.5% Physics  x /  y 574 nm / 6 nm  z 300  m  x /  y 10  m / 35 nm  x /  y 11 mm / 0.48 mm bunch charge2×10 10 Beam (interaction point) Number of bunches / pulse1312 Bunch spacing554 ns Pulse current5.8 mA Beam pulse length727  s Pulse repetition rate5 Hz Beam (time structure) Average beam power10.5 MW (total) Total AC power163 MW (linacs AC power107 MW) Accelerator (general) N. Walker (DESY) – ILC Worldwide Event – CERN – 12 June 20134 tiny emittances nano-beams at IP strong beam-beam tiny emittances nano-beams at IP strong beam-beam High-power high-current beams. Long bunch trains.  SCRF

29. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 29 The Japanese Interest to Host ILC Project > The completion of the Technical Design Report on the ILC and the low Higgs mass have triggered strong interest to host and provide host state funding for ILC in Japan. > N. Walker: “Looking towards East…” From Nick Walker

30. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 30 Outline > Acceleration in metallic RF structures > Towards high luminosity > Higgs collider concepts with leptons > “New” ideas and concepts > Conclusion

31. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 31 R&D on Lower Cost Alternatives for the Long Term…

32. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 32 Reminder: Plasma-Acceleration (Internal Injection)

33. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 33 Reminder: Plasma-Acceleration (Internal Injection)

34. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 34 Reminder: Plasma-Acceleration (Internal Injection)

35. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 35 Reminder: Plasma-Acceleration (Internal Injection)

36. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 36 And Plasma Acceleration (trapping) Works…

37. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 37 Slide by V. Malka

38. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 38 Critical, Missing Step: Make it Useful for Something...

39. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 39

40. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 40 EAAC 2013

41. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 41 Pointing out some European efforts…

42. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 42 Ongoing Required Work: Lasers with 30% Efficiency Coherent Amplification Network

43. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 43 HEP lab: Plasma Acceleration R&D at CERN  AWAKE Figures: A. Caldwell et al

44. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 44 HEP and photon science lab: DESY Accelerator R&D FLASHForward

45. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 45 DESY: DORIS into Accelerator R&D Facility? ERC Grant Pro- posal Kärtner, Aßmann, Chap-man, Fromme: THz injector for atto-s bunches ARD collabora- tion on very short bunches (DESY, Uni HH, KIT, …) LAOLA-ARD experiments (DESY, Uni HH, …) on staged, ultra-high gradient plasma acceleration Room for addi- tional experi- ments: the PIER Voss-Wideröe Center will be a forum to call for proposals

46. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 46 Conclusions I

47. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 47 Conclusions II

48. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 48 Towards the table-top, really compact accelerator…

49. Ralph Aßmann | EPS-HEP2013 | 23.07.2013 | Page 49 … for high power physicists Thank you for your attention!