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The Beta-beam beta-beam.web.cern.ch/beta-beam/

The Beta-beam http://beta-beam.web.cern.ch/beta-beam/. Mats Lindroos on behalf of the The BENE beta-beam network. Collaborators. BENE beta-beam network: GSI: Helmuth Weick, Markus Steck, Peter Spiller, Oliver Boine-Frankenheim, R. Hollinger, B. Franzke CEA:

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The Beta-beam beta-beam.web.cern.ch/beta-beam/

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  1. The Beta-beamhttp://beta-beam.web.cern.ch/beta-beam/ Mats Lindroos on behalf of the The BENE beta-beam network BENE beta-beam network

  2. Collaborators • BENE beta-beam network: • GSI: • Helmuth Weick, Markus Steck, Peter Spiller, Oliver Boine-Frankenheim, R. Hollinger, B. Franzke • CEA: • Olivier NAPOLY, Jacques Payet, Jacques Bouchez • IN2P3: • Cristina Volpe, Alex Muelle, Pascal Sortais, Laune Bernard, Antonio Villar • INFN: • Vittorio Palladino, Mauro Mezzetto, Alberto Facco, Andrea Pisent • UK: • Chris Prior, Marielle Chartier • CERN: • Mats Lindroos, Steven Hancock, Matteo Magistris, Simone Gilardoni, Fredrik Wenander, Roland Garoby, Michael Benedikt, Ulli Koester • Geneva University: • Alain Blondel • Louvain-la-neuve: • Guido Ryckewaert, Thierry Delbar • Uppsala: • Dag Reistad • Associate: • Andreas Jansson, Rick Baartman BENE beta-beam network

  3. Acknowledgements • For kindly having assisted with this specific presentation: • M.Benedikt, A.Blondel, J.Bouchez, K.Elsener, S.Gilardoni, R.Garoby, S.Hancock, A.Jansson, U.Koester M.Magistris, S.Russenschuck, P.Sortais, C.Volpe, F.Wenander BENE beta-beam network

  4. Outline • Neutrino oscillations • The beta-beam • Overview • The CERN base line scenario • The Moriond workshop • The super beam • Conclusions BENE beta-beam network

  5. Neutrinos • A mass less particle predicted by Pauli to explain the shape of the beta spectrum • Exists in at least three flavors (e, m, t) • Could have a small mass which could significantly contribute to the mass of the universe • The mass could be made up of a combination of mass states • If so, the neutrino could “oscillate” between different flavors as it travel along in space BENE beta-beam network

  6. n3 Dm223= 3 10-3eV2 n2 n1 Dm212= 3 10-5 - 1.5 10-4 eV2 OR? n2 n1 Dm212= 3 10-5 - 1.5 10-4 eV2 Dm223= 3 10-3eV2 n3 q23(atmospheric) = 450 , q12(solar) = 300 , q13(Chooz) < 130 Unknown or poorly known even after approved program: 13 , phase  , sign of Dm13 Neutrino oscillations • Three neutrino mass states (1,2,3) and three neutrino flavors (e,m,t) 2 BENE beta-beam network A. Blondel

  7. Objectives • The beta-beam could be one component in the future European Neutrino Physics programme • Present a coherent and “realistic” scenario for a beta-beam facility: • Use known technology (or reasonable extrapolations of known technology) • Use innovations to increase the performance • Re-use a maximum of the existing accelerators BENE beta-beam network

  8. Nuclear Physics CERN: b-beam baseline scenario Decay ring Brho = 1500 Tm B = 5 T Lss = 2500 m SPL SPS Decay Ring ISOL target & Ion source ECR Cyclotrons, linac or FFAG Rapid cycling synchrotron PS BENE beta-beam network

  9. Desired beam parameters in the decay ring 6Helium2+ • Intensity: 1.0x1014 ions • Energy: 139 GeV/u • Rel. gamma: 150 • Rigidity: 1500 Tm 18Neon10+ • Intensity: 4.5x1012 ions • Energy: 55 GeV/u • Rel. gamma: 60 • Rigidity: 335 Tm • The neutrino beam at the experiment will have the “time stamp” of the circulating beam in the decay ring. • We need to concentrate the beam in as few and as short bunches as possible to maximize the number of ions/nanosecond. (background suppression) • Clearly 6He is the more demanding ion and considered further on . BENE beta-beam network

  10. SPL, ISOL and ECR Objective: • Production, ionization and pre-bunching of ions Challenges: • Production of ions with realistic driver beam current • Target deterioration • Accumulation, ionization and bunching of high currents at very low energies SPL ISOL Target + ECR Linac, cyclotron or FFAG Rapid cycling synchrotron PS SPS Decay ring BENE beta-beam network

  11. 6He production by 9Be(n,a) Converter technology: (J. Nolen, NPA 701 (2002) 312c) Layout very similar to planned EURISOL converter target aiming for 1015 fissions per s. BENE beta-beam network

  12. Mercury jet converter H.Ravn, U.Koester, J.Lettry, S.Gardoni, A.Fabich BENE beta-beam network

  13. Production of b+ emitters Scenario 1 • Spallation of close-by target nuclides:18,19Ne from MgO and 34,35Ar in CaO • Production rate for 18Ne is 1x1012 s-1 (with 2.2 GeV 100 mA proton beam, cross-sections of some mb and a 1 m long oxide target of 10% theoretical density) • 19Ne can be produced with one order of magnitude higher intensity but the half life is 17 seconds! Scenario 2 • alternatively use (,n) and (3He,n) reactions: 12C(3,4He,n)14,15O, 16O(3,4He,n)18,19Ne, 32S(3,4He,n)34,35Ar • Intense 3,4He beams of 10-100 mA 50 MeV are required BENE beta-beam network

  14. MONOECR (at ISOLDE) target side extraction target ECR volume extraction side ~250 mm ~250 mm • MINIMONO ISOLDE • GANIL design [1,2] • ‘standard’ ISOLDE unit • permanent magnets • consumable unit • on-line test 2003 • ISOECRIS • based on a ISOLDE unit • coils • consumable unit • in production F. Wenander, J.Lettry BENE beta-beam network

  15. 60-90 GHz « ECR Duoplasmatron » for gaseous RIB 2.0 – 3.0 T pulsed coils or SC coils Very high density magnetized plasma ne ~ 1014 cm-3 Very small plasma chamber F ~ 20 mm / L ~ 5 cm Target Arbitrary distance if gas Rapid pulsed valve • 1-3 mm 100 KV extraction 60-90 GHz / 10-100 KW 10 –200 µs /  = 6-3 mm optical axial coupling UHF window or « glass » chamber (?) 20 – 100 µs 20 – 200 mA 1012 to 1013 ions per bunch with high efficiency Moriond meeting: Pascal Sortais et al. ISN-Grenoble optical radial coupling (if gas only) BENE beta-beam network

  16. Low-energy stage Objective: • Fast acceleration of ions and injection • Acceleration of 16 batches to 20 MeV/u SPL ISOL Target + ECR Linac, cyclotron or FFAG Rapid cycling synchrotron PS SPS Decay ring BENE beta-beam network

  17. Rapid Cycling Synchrotron Objective: • Accumulation, bunching (h=1), acceleration and injection into PS Challenges: • High radioactive activation of ring • Efficiency and maximum acceptable time for injection process • Charge exchange injection • Multiturn injection • Electron cooling or transverse feedback system to counteract beam blow-up? SPL ISOL Target + ECR Linac, cyclotron or FFAG Rapid cycling synchrotron PS SPS Decay ring BENE beta-beam network

  18. Overview: Accumulation • Sequential filling of 16 buckets in the PS from the storage ring BENE beta-beam network

  19. PS • Accumulation of 16 bunches at 300 MeV/u • Acceleration to g=9.2, merging to 8 bunches and injection into the SPS • Question marks: • High radioactive activation of ring • Space charge bottleneck at SPS injection will require a transverse emittance blow-up SPL ISOL Target + ECR Linac, cyclotron or FFAG Fast cycling synchrotron PS SPS Decay ring BENE beta-beam network

  20. SPS PS PS PS PS Overview:PS to SPS • Merging in PS to 8 buckets • Blow-up before transfer to manage space charge limit in SPS SPS PS BENE beta-beam network

  21. SPS Objective: • Acceleration of 8 bunches of 6He(2+) to g=150 • Acceleration to near transition with a new 40 MHz RF system • Transfer of particles to the existing 200 MHz RF system • Acceleration to top energy with the 200 MHz RF system • Ejection in batches of four to the decay ring Challenges: • Transverse acceptance SPL ISOL Target + ECR Linac, cyclotron or FFAG Fast cycling synchrotron PS SPS Decay ring BENE beta-beam network

  22. Decay ring Objective: • Injection of 4 off-momentum bunches on a matched dispersion trajectory • Rotation with a quarter turn in longitudinal phase space • Asymmetric bunch merging of fresh bunches with particles already in the ring SPL ISOL Target + ECR Linac, cyclotron or FFAG Fast cycling synchrotron PS SPS Decay ring BENE beta-beam network

  23. Injection into the decay ring • Bunch merging requires fresh bunch to be injected at ~10 ns from stack! • Conventional injection with fast elements is excluded. • Off-momentum injection on a matched dispersion trajectory. • Rotate the fresh bunch in longitudinal phase space by ¼ turn into starting configuration for bunch merging. • Relaxed time requirements on injection elements: fast bump brings the orbit close to injection septum, after injection the bump has to collapse within 1 turn in the decay ring (~20 ms). • Maximum flexibility for adjusting the relative distance bunch to stack on ns time scale. BENE beta-beam network

  24. SPS SPS SPS Overview: Decay ring • Ejection to matched dispersion trajectory • Asymmetric bunch merging BENE beta-beam network

  25. Horizontal aperture layout • Assumed machine and beam parameters: • Dispersion: Dhor = 10 m • Beta-function: bhor = 20 √m • Moment. spread stack: Dp/p = ±1.0x10-3 (full) • Moment. spread bunch: dp/p = ± 2.0x10-4 (full) • Emit. (stack, bunch): egeom = 0.6 pmm Beam: ± 2 mm momentum ± 4 mm emittance Required bump: 22 mm Required separation: 30 mm, corresponds to 3x10-3 off-momentum. Septum & alignment 10 mm Stack: ± 10mm momentum ± 4 mm emittance 22 mm Central orbit undisplaced M. Benedikt BENE beta-beam network

  26. Injection to decay ring BENE beta-beam network M. Benedikt

  27. Asymmetric bunch merging S. Hancock BENE beta-beam network

  28. Full scale simulation with SPS as model • Simulation conditions: • Single bunch after injection and ¼ turn rotation. • Stacking again and again until steady state is reached. • Each repetition, a part of the stack (corresponding to b-decay) is removed. • Results: • Steady state intensity was ~85 % of theoretical value (for 100% effective merging). • Final stack intensity is ~10 times the bunch intensity (~15 effective mergings). • Moderate voltage of 10 MV is sufficient for 40 and 80 MHz systems for an incoming bunch of < 1 eVs. BENE beta-beam network

  29. Decay losses • Acceleration losses: A. Jansson BENE beta-beam network

  30. How bad is 9 W/m? • For comparison, a 50 GeV muon storage ring proposed for FNAL would dissipate 48 W/m in the 6T superconducting magnets. Using a tungsten liner to • reduce peak heat load for magnet to 9 W/m. • reduce peak power density in superconductor (to below 1mW/g) • Reduce activation to acceptable levels • Heat load may be OK for superconductor. BENE beta-beam network

  31. SC magnets • Dipoles can be built with no coils in the path of the decay (one ion type) particles to minimise peak power density in superconductor (quench stability). S. Russenschuck, CERN BENE beta-beam network

  32. Tunnels and Magnets • Civil engineering costs: Estimate of 400 MCHF for 1.3% incline (13.9 mrad) • Ringlenth: 6850 m, Radius=300 m, Straight sections=2500 m • Magnet cost: First estimate at 100 MCHF Arc cross-section CERN Cricket Club Tunnel Shielding BENE beta-beam network

  33. Intensities: 6He • From ECR source: 2.0x1013 ions per second • Storage ring: 1.0x1012 ions per bunch • Fast cycling synch: 1.0x1012 ion per bunch • PS after acceleration: 1.0x1013 ions per batch • SPS after acceleration:0.9x1013 ions per batch • Decay ring: 2.0x1014 ions in four 10 ns long bunch • Only b-decay losses accounted for, efficiency <50% BENE beta-beam network

  34. Intensities: 18Ne • From ECR source: 0.8x1011 ions per second • Storage ring: 4.1x1010 ions per bunch • Fast cycling synch: 4.1x1010 ion per bunch • PS after acceleration: 5.2x1011 ions per batch • SPS after acceleration:4.9x1011 ions per batch • Decay ring: 9.1x1012 ions in four 10 ns long bunch • Only b-decay losses accounted for, efficiency <50% BENE beta-beam network

  35. Moriond meeting • Annual electro week meeting in Les Arcs • Workshop on Radioactive beams for Nuclear and Neutrino Physics • Organizer: Jacques Bouchez, CEA, Saclay • Many new ideas, among them: • Multiple targets for Ne production • ECR bunching (P. Sortais) • Ne and He in the decay ring simultaneously • Low energy beta facility (C. Volpe) • GSI, GANIL and CERN (in close detector) BENE beta-beam network

  36. Ne and He in decay ring simultaneously • Enormous “gain” in counting time • Years! • Requiring g=150 for He will at equal rigidity result in a g=250 for Ne • Physics? • Detector simulation should give “best” compromise • Requiring equal revolution time will result in a DR of 20 mm (R0=1090 m) • Manageable? BENE beta-beam network

  37. 6He 8 s SPS cycling Accumulation (multiplication) factor 6He 16 s SPS cycling Time (s) Requires larger long. Acceptance! Accumulation Ne + He BENE beta-beam network

  38. CERN Geneve • SPL @ CERN • 2.2GeV, 50Hz, 2.3x1014p/pulse • 4MW Now under R&D phase 130km 40kt 400kt Italy CERN to FREJUS BENE beta-beam network

  39. The Super Beam BENE beta-beam network

  40. HERE : 250 MeV NEUTRINOS BENE beta-beam network

  41. Water CherenkowSuper Kamiokande MultiUSER detector: Astrophysics, Beta-beam, Super Beam, Proton Decay BENE beta-beam network

  42. T CP CP T Combination of beta beam with low energy super beam Unique to CERN: combines CP and T violation tests e m (+) m e (p+) e m (-) m e (p-) A. Blondel BENE beta-beam network

  43. SPL (8 MW) for many users 3ms 2.2 GeV for NuFact and Super Beam 15 mA 15 ms accelerated to 2.2 GeV for other Users b beam 3 mA 20 ms total power at 2.2 GeV 4 MW X 2 = 8 MW BENE beta-beam network

  44. Physics reach M. Mezzetto BENE beta-beam network

  45. Superbeam & Beta Beam cost estimates (NUFACT02) BENE beta-beam network

  46. Conclusions • Physics: • Strong interest from community • Super beam, beta-beam and FREJUS: WORLD unique • Low energy beta-beam: other sites • A baseline scenario for the beta-beam exists • While, possible solutions have been proposed for all identified bottlenecks we still have problems to overcome but… • …you are invited to make proposals for improvements! • Higher intensity in the decay ring • First results are so encouraging that the beta-beam option should be fully explored BENE beta-beam network

  47. Open questions… …among them • Target (area) design • EURISOL study (Design study in 6th EU FP) • Efficiency of ECR chargebreeding and bunching • Low energy acceleration • LINAC/ECR/FFAG? • Combined storage ring and Rapid Cycling Synchrotron • Injection into Rapid Cycling Synchrotron • PS – do we need a new (Rapid cycling) machine? • Space charge bottle neck from PS to SPS • Lattice for decay ring • Many constraints if Ne and He should be stored simultaneously • Stability of short high intensity ion bunches in decay ring • Magnet design for decay ring • Civil engineering of decay ring • Shielding issues to avoid groundwater activation BENE beta-beam network

  48. Comment • We are all working hard to complete the LHC and to keep CERN running… • In your already overloaded week try to find 2 hours… • Spend one of these hours on our future • CLIC • Nufact • Beta-beam • And many more ideas • Spend the other hour on LHC • The succesfull completion of LHC is conditional for any long term future of CERN • Thank you for your attention! BENE beta-beam network

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