SPL R&D and Potential Applications

1. SPL R&D and Potential Applications R. Garoby for the SPL team* O. Brunner, S. Calatroni, O. Capatina, E. Ciapala, F. Gerigk, E. Montesinos, V. Parma, K.M. Schirm, + I. Aviles Santillana **, R. Bonomi **, J. Chambrillon, P. Coelho Azevedo**, K. Liao, N. Valverde Alonso** ** supported by ESS

2. HP-SPL:R&D Management

3. Resources • R & D for a High Power SPL formally supported at CERN in view of multiple future potential applications • ~1.7 MCHF and 6 FTEs / year • Collaboration with ESS • Fellows and procurement of klystron modulator for SM18 • French in-kind contribution • Tuners, Helium tanks, use of Saclay 704 MHz high power test place… • EC-supported programmes • EuCARD (WP10) • Development and test of beta=1 (CEA) and beta=0.65 (IN2P3) 5 cells cavities • CRISP (WP4) • Joint work with ESS and DESY • EC-supported manpower for upgrading and exploiting the SM18 test place • LAGUNA-LBNO • EC-supported fellow for studying proton drivers at CERN using LP- or HP-SPL • DOE-supported programme • BNL • Development and test of a b=1 cavity • SPL documentation in EDMS [ https://edms.cern.ch/nav/SLHC-000008 ] • SPL meetings in Indico [ http://indico.cern.ch/categoryDisplay.py?categId=1893 ]

4. Organization (at CERN) Guideline «Project-like» structure aimedat meeting the objectives of the HP-SPL R&D: • Building and testing a prototype cryomodule with 4 cavities • Updating CERN infrastructure and competence in superconducting RF technology • Preparingsubmission of future subjects of R&D [design and construction of a full-size cryomodule, high power RF sources, HIPIMS (High Power Impulse Magnetron Sputtering)…] WorkUnits • Design, construction and test of the prototype cryomodule (Leader: V. Parma) • Components: Cryomodule, Cavities, RF items (Couplers, tuners, …), cryogenicsequipment… • Assembly (withadequatetools): cavities string in clean room, inclusion in cryomodule • Tests: cavities in vertical cryostat, assembledcryomodule in bunker. • Upgrade of the SM18 infrastructure (Leader: O. Brunner) • HP water rinsing system and upgraded clean roon • Cryogenics for efficient operationat 2K • High power RF at 704 MHz (klystron, modulator, high power distribution) • LowLevel RF and controls • SC RF cavitiestechnology (Leader: E. Ciapala) • Fabrication and processing • Test, diagnostics and analysis

5. HP-SPL:Baseline Design Parameters

6. HP-SPL: BeamCharacteristics Required for low loss in accumulator Ion species H− Output Energy 5 GeV Bunch Frequency 352.2 MHz Repetition Rate 50 Hz High speed chopper < 2 ns (rise & fall times) Required for muon production Required for flexibility and low loss in accumulator 2 ´ beam current Þ 2 ´ nb. of klystrons etc .

7. HP-SPL: Block Diagram 110 m 0.73 GeV 0 m 0.16 GeV 291 m 2.5 GeV 500 m 5 GeV Medium b cryomodule High b cryomodules High b cryomodules Debunchers Ejection From Linac4 To HP-PS and/or Accumulator to EURISOL 9 x 6 b=0.65 cavities 13 x 8 b=1 cavities 11 x 8 b=1 cavities • Segmentedcryogenics / separatecryo-line / room temperaturequadrupoles: • Medium b (0.65) – 3 cavities / cryomodule • High b (1) – 8 cavities / cryomodule Low energy Intermediate energy High energy

8. HP-SPL: Cavities & Cromodules Energy gain (MeV/m) Medium b cryomodule Energy range: 160 MeV – 732 MeV 5 cell cavities Geometrical b: 0.65 Maximum energy gain: 19.4 MeV/m 54 cavities (9 cryomodules) Length of medium b section: ~110.35 m 1 5 10 15 100 200 300 400 High b cryomodule Position (m) Energy range: 732 MeV – 5 GeV 5 cell cavities Geometrical b: 1 Maximum energy gain: 25 MeV/m 192 cavities (24 cryomodules) Length of high b section: ~360 m

9. Status and Plans of R&D

10. Cavities (1/4)

11. Cavities (2/4)

12. Cavities (3/4)

13. Cavities (4/4)

14. SPL coupler: requirements

15. SPL coupler: 2 designs SPS-derived LHC-derived Ceramic window Doubled-wall tube Air cooling

16. SPL coupler: test assembly • Four ‘vacuum lines’: • 4 cylindrical window couplers • 4 planar disk window couplers • 8 Double walled Tubes • 4 test boxes • DESY clean process assembly • (Jlab also proposed to help) • CERN LLRF measurements • CEA RF power tests • (BNL also proposed to help)

17. SPL coupler: clean room assembly (DESY) • Test box assembly not easy because of specific surfaces roughness needed for helicoflex • Couplers assembly was also not easy because : • Couplers are heavy • Last connection has to be done manually • Ok for few prototypes, not for a large series

18. SPL coupler: RF high power tests (CEA) • Tests started with cylindrical window couplers • Not baked out, static vacuum ~ 2 x 10 -7 mbar • Wanted to check RF • Size of the test box 250 mm x 600 mm • Helicoflex • Pulse mode process • Reached > 1MW – 25 Hz – 2 ms (limited by heating due to lack of Cu platting)

19. Short cryomodule: the actors ESS/CERN Fellow ESS/CERN Fellow ESS/CERN Fellow ESS/CERN Fellow

20. Short cryomodule: schematic layout Connection to cryo distribution line Technical Service Module End Module Cryo fill line (Y), top left Phase sep. Now suppressed Inter-cavity support CW transition Cavity additional support RF coupler, bottom left side Now suppressed 1.7% Slope (adjustable 0-2%)

21. Short cryomodule: vacuum vessel • General concept and dimensions (not latest design) 1054 Transport,dressing and alignment frame SSS 1021 7400 CourtesyP.Duthil (IPNO) (views S.Rousselot, IPN-Orsay)

22. Short cryomodule: technical service module Ph.Separator pot 4.5 K vapor generator reservoir (with elect.heater) Last cavity IC support CWT 50 K heat intercept DN80 gate valve (single valve) standard support CourtesyP.Duthil (IPNO) (views S.Rousselot, IPN-Orsay)

23. LLRF underdevelopment D. Valuch

24. Upgraded installation in SM18

25. Short cryomodule: master schedule Preparation of SM18 infrastructure (cryogenics, RF, clean-room) Delivery of 704 MHz klystron and modulator Cavities production Cavities processing/RF testing RF couplers Clean room assembly of string Cryomodule (& assy tooling) design Cryomodule fabrication Cryomodule assembly Start cryomodule RF testing

26. Related R & D Nb coating of Cu cavities, using the HIPIMS (High Power Impulse Magnetron Sputtering) technology • In collaboration with Sheffield Hallam University (UK). • Supported in the context of the construction of LHC spare cavities. • Potentially very attractive technology for the SPL (raw material cost, mechanical stiffness). • First results on low beta 704 MHz cavity: end 2012

27. SPL Applicationsto Proton Drivers

28. 50 GeV synchrotron-based proton driver • New High Power PS (30-50 GeV, 2MW beam power) using the Low Power SPL (LP-SPL) as injector. • FeasibilityStudybased on the work for SPL and PS2 supportedwithin the LAGUNA-LBNO DS. Long baseline experiment (2300 km) CERN-Pyhasalmi (Finland)

29. PS2 parameters: reminder… 29

30. PS2 integrationat CERN: reminder • “Straight” H- inj. line SPL  PS2 avoiding large bending radii to minimise Lorentz stripping of H-. • Minimum length of inj. line TT10  PS2 for ions and protons from PS complex. • Minimum length HE line PS2  SPS. SPS PS2 to SPS PS2 PS/LEIR to SPS / PS2 SPL to PS2 SPL PS Linac4 PAC 2009 Vancouver PS2 Design Optimization, M.Benedikt 30

31. HP-SPL based proton driver: principle (1/2) SPL-based 5 GeV – 4 MW proton drivers have been designed [SPL + 2 fixed energy rings (accumulator & compressor)] which meet these requirements References: • SPL based proton driver/ R. Garoby, talk at NuFact06, http://nufact06.physics.uci.edu/Workshop/Slides/RGaroby_SPL3_Pdriver.ppt • Feasibility Study of Accumulator and Compressor for the 6-bunches SPL-based Proton Driver / M. Aiba, CERN-AB-2008-060 • A first analysis of 3-bunches and 1-bunch scenario for the SPL-based Proton Driver / M. Aiba, CERN-AB-Note-2008-048-BI • Beam Stability in the SPL Proton Driver Accumulator for a Neutrino Factory at CERN / E. Benedetto, http://nufact09.iit.edu/wg3/wg3_benedetto-splstability.ppt, to be published • SPL-based Proton Driver for a Neutrino Factory at CERN, M. Aiba, E. Benedetto, R. Garoby, M. Meddahi, poster nb.25 (this workshop) Specifications (from ISS report)

32. HP-SPL based proton driver: principle (2/2) • Beam accumulation • Accumulator ring • Charge exchange injection • n x 100ms accumulation time • Isochronous (h=0): beam frozen longitudinally to preserve Dp/p • No RF (=> minimum impedance) • 1-6 bunches of ~120 ns length • Bunch compression • Compressor ring • Large RF voltage (large stored energy & minimum RF power) (=> bunch rotation on stored energy) • Large slippage factor h => rapid phase rotation in few x10ms, • ~2ns rms bunch length @ extraction to the target (=> moderate DQ because of dispersion) • Synchronization between rings - Ratio of circumferences guaranteeing correct positioning of successive bunches inside the compressor without energy change in any ring

33. Generation of 6 bunches Accumulator [120 ns pulses - 60 ns gaps] SPL beam [42 bunches - 21 gaps] Compressor [120 ns bunch - V(h=3) = 4 MV] Target [2 ns bunches – 6 times]

34. Bunch rotation beforeejection from M. Aiba

35. Main parameters from M. Aiba

36. Beam delivery on 4 targets & horns E. Bouquerel – IPHC, EUROnu meeting, March 27, 2012 side view >>KEY PARAMETER<< Angle of deflection (rad) Magnetic field (T) 2000mm T1 T2 Kinetic energy (GeV) 3D view Magnetic length (m) Principle: z T3 T4 • Use of 2 bipolar kickers (or bipolar pulsed magnets): ± 45˚ rotation wrt the z axis • K1 (K2) deflects to D1 and D3 (D2 and D4) • Need of 1 compensating dipole per beam line (1 angle for each target): • Apply a symmetry in the system

37. Summary

38. Technology (1/2) Presently, the HP-SPL R&D: • progresses at a good pace, leading to the high power test of a short 4 cavities cryomodule in 2014. • allowstesting the validity of new concepts thatshouldresult in significantsavings (RF couplers, SS He tanks, Cryomodule design…) • canpotentiallybeused in multiple projectsat CERN as well as outside (ESS, MYRRHA) and benefitsfromexternal support (ESS and EU programmes) • isa means for CERN to embedinside the network of labsinvolved in superconducting RF technology (CEA, IN2P3, DESY, JLAB, FNAL, ANL…) and re-establishin-house competencein thatfieldatthe state-of-the-art level • drives infrastructural upgrades (e.g. electro-polishingfacility, clean room, high power RF at 704 MHz…) whichwillbebeneficial for otherdevelopment (LHC main RF, Crabcavities, HIE IDOLDE…)

39. Technology (2/2) Important future R&D subjects • HOM damper for beamstabilityat high current • Cavities in view of reaching the expected performance/simplifying fabrication/evaluating alternative solutions (Nb on Cu) • Cryomoduletowards a full size prototype • RF amplifiersfor reducingcost • Power supplyfor high power amplifier for reducingcost

40. Accelerator design • The SPL acceleratordesign is«mature» and stable • In the context of the LAGUNA-LBNO: • The LP-SPL design willbeadapted to the requirements of the HP-PS • The HP-SPL design willbebrieflyrevisited and completedwith the design of the accumulation ring • Other applications mayrequireresuming/refiningaccelerator design: • e+/e- acceleration in the ERL of the Linac-Ring option of LHeC • LEP-3 • LP-SPL remains a back-up option for the LHC injectorcomplex…

41. THANK YOU for your attention!