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Beta-Beams

Beta-Beams. Elena Wildner, CERN. 1. Outline. Beta Beam Concepts The Beta Beam Scenario The challenges Isotope production Accelerating ions Intensities Radioactivity Backgrounds & accelerators Other studies Conclusion. 2. 2. Beta-beams, recall 1. Aim:

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Beta-Beams

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  1. Beta-Beams Elena Wildner, CERN Neutrino Summer School 2010: Beta Beams, Elena Wildner 1

  2. Outline • Beta Beam Concepts • The Beta Beam Scenario • The challenges • Isotope production • Accelerating ions • Intensities • Radioactivity • Backgrounds & accelerators • Other studies • Conclusion 2 2 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  3. Beta-beams, recall 1 Aim: Production of (anti-)neutrino beams from the beta decay of radio-active ions circulating in a storage ring with long straight sections. • Similar to the neutrino factory concept, but the parent particle is a beta-active isotope instead of a muon. Beta-decay at rest • n-spectrum well known from the electron spectrum • Reaction energy Q typically of a few MeV 3 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  4. Storage ring with long straight sections n-beam Ion Linac 25 MeV, 7 Li and 6 Li 8B/8Li PR Ion production Decay ring: Storage of ions Decay in the long straight sections ISOL target, Collection SPS Neutrino Source Decay Ring Existing!!! 60 GHz pulsed ECR PS Linac, 100 MeV 280 GeV RCS, 1.7 GeV Neutrino Summer School 2010: Beta Beams, Elena Wildner

  5. Beta-beams, recall 2 Accelerate parent ion to relativistic gmax Boosted neutrino energy spectrum: En  2gQ Forward focusing of neutrinos:   1/g Pure electron (anti-)neutrino beam! Depending on b+- or b- - decay we get a neutrino or anti-neutrino Two different parent ions for neutrino and anti-neutrino beams Physics applications of a beta-beam Primarily neutrino oscillation physics and CP-violation (high energy) Cross-sections of neutrino-nucleus interaction (low energy) E0 5 5 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  6. t1/2 at rest (ground state) 1ms – 1s 1 – 60 s NuBase Choice of radioactive ion species • Beta-active isotopes • Production rates • Life time • Dangerous rest products • Reactivity (Noble gases are good) • Reasonable lifetime at rest • If too short: decay during acceleration • If too long: low neutrino production • Optimum life time given by acceleration scenario • In the order of a second • Low Z preferred • Minimize ratio of accelerated mass/charges per neutrino produced • One ion produces one neutrino. • Reduce space charge problems 6He and 18Ne 8Li and 8B 6 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  7. Beta beam options • High Energy beta beams >100 MeV • Available accelerators (or funding) • Synergies with super-beams (nm and nm) • Available detectors • Physics reach: choice of baseline (distance to detector) • See talk by Mauro Mezetto • Low energy beta beams < 50 MeV • Off axis experiments • Low energy storage rings • Available detectors 7 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  8. Neutrino energy: Q and g • Accelerators can accelerate ions up to Z/A × the proton energy • Limitsg • L ~ <En > / Dm2 ~ gQ , Flux ~ L−2 => Flux ~ Q −2 • Cross section ~ <En > ~ gQ • Merit factor (Flux * Cross-section) for an experiment at the atmospheric oscillation maximum: M= g/Q • Remember: ion lifetime ~ g , therefore we need longer straight sections in the decay ring to give the same flux for the same number of stored ions in the accelerator. 8 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  9. High g and decay-ring size, 6He Example : Neutrino oscillation physics with a higher gb-beam, arXiv:hep-ph/0312068 J. Burguet-Castell, D. Casper, J.J. Gomez-Cadenas, P.Hernandez, F.Sanchez 9 9 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  10. Beta beam to different baselines 10 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  11. BASELINE PHYSICS POTENTIAL n n-nucleus cross sections (detector’s response, r-process, 2b-decay) SPS storage ring PS fundamental interactions studies (Weinberg angle, CVC test, mn) astrophysical applications Low energy Beta Beams Christina Volpe: A proposal to establish a facility for the production of intense and pure low energy neutrino beams. J Phys G30 (2004) L1. To off axis far detector close detector n PHYSICS STUDIED WITHIN THE EURISOL DS (FP6, 2005-2009) 11 11 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  12. Acceleration of ions for beta beams Production and low energy Production of useful isotopes (neutrino emitters in particular) Collect the produced ions Ionize and extract the isotopes for the first acceleration step (several charge states or low charge states) First acceleration and stripping Accelerate high intensities to high energies Relatively straight forward: can we use existing accelerators ? Bunch structures Instabilities in machines Store high intensities 12 12 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  13. The EURISOL scenario boundaries Based on CERN boundaries Ion choice: 6He and 18Ne Based on existing technology and machines Ion production through ISOL technique Bunching and first acceleration: ECR, linac Rapid cycling synchrotron Use of existing machines: PS and SPS Relativistic gamma=100 for both ions SPS allows maximum of 150 (6He) or 250 (18Ne) Gamma choice optimized for physics reach Opportunity to share a Mton Water Cherenkov detector with a CERN super-beam, proton decay studies and a neutrino observatory Achieve an annual neutrino rate of 2.9*1018 anti-neutrinos from 6He 1.1 1018 neutrinos from 18Ne The EURISOL scenario will serve as reference for further studies and developments: Within Euron we will study 8Li and 8B top-down approach (*) EURISOL scenario (*) 2010-06-15 02/10/09 13 13 13 FP6 “Research Infrastructure Action - Structuring the European Research Area” EURISOL DS Project Contract no. 515768 RIDS Neutrino 2010 (Athens): Beta Beams, Elena Wildner

  14. Beta Beam scenario 6He/18Ne 18Ne Isotopes is not possible to produce with ISOL technology: New Ideas are needed!!! n-beam to Frejus Super Proton Linac Decay ring Br ~ 500 Tm B = ~ 6 T C = ~ 6900 mLss= ~ 2500 m 6He: g = 100 18Ne: g = 100 Ion production 6He/18Ne ISOL target SPS Neutrino Source Decay Ring Existing!!! 60 GHz pulsed ECR PS Linac, 100 MeV/n 450 GeVp RCS Neutrino Summer School 2010: Beta Beams, Elena Wildner

  15. New approaches for ion production “Beam cooling with ionisation losses” – C. Rubbia, A Ferrari, Y. Kadi and V. Vlachoudis in NIM A 568 (2006) 475–487 “Development of FFAG accelerators and their applications for intense secondary particle production”, Y. Mori, NIM A562(2006)591 Supersonic gas jet target, stripper and absorber Studied within Euron FP7 (*) FP7 “Design Studies” (Research Infrastructures) EUROnu (Grant agreement no.: 212372) (*) European Strategy for Future Neutrino Physics, Elena Wildner Neutrino Summer School 2010: Beta Beams, Elena Wildner

  16. Beta Beam scenario 8Li/8B n-beam to Gran Sasso or Canfranc Ion Linac 25 MeV, 7 Li and 6 Li 8B/8Li PR Ion production Decay ring Br ~ 500 Tm B = ~6 T C = ~6900 mLss= ~2500 m 8Li: g = 1008B: g = 100 ISOL target, Collection SPS Neutrino Source Decay Ring Existing!!! 60 GHz pulsed ECR PS Linac, 100 MeV 280 GeV RCS, 1.7 GeV Neutrino Summer School 2010: Beta Beams, Elena Wildner

  17. PR: Gas Jet Targets and Cooling (GSI) We need 10 19 cm-2 !! Neutrino Summer School 2010: Beta Beams, Elena Wildner

  18. Challenge: collection device A large proportion of beam particles (6Li) will be scattered into the collection device. Production of 8Li and 8B: 7Li(d,p) 8Li and 6Li(3He,n) 8B reactions using low energy and low intensity ~ 1nA beams of 7Li(10-25 MeV) and 6Li(4-15 MeV) hitting the deuteron or 3Hetarget. • Semen Mitrofanov • Thierry Delbar • Marc Loiselet End of the summer 2010 - 8Li collection will be measured! Research on B will follow. Neutrino Summer School 2010: Beta Beams, Elena Wildner

  19. X-sections, Energies and Angles, Li and B Inverse kinematic reaction (heavy ion beam on light target): 7Li + CD2 target Ebeam=25 MeV Why? Reaction products in forward cone (~15 degrees), facilitates collection. Beam traverses target with relatively limited changes (momentum, angle) 8B production experiments are being planned at Legnaro INFN-LNL: M. Cinausero, G. De Angelis, G. Prete, E Vardaci 19 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  20. ECR (60 GHz) Source (1) • Ions effuse into the source • Very strong magnetic fields and electromagnetic fields • Confinement • Plasma (60 GHz) • They leave the source with a certain emittance • The emmittance defines the properties of the beam after the source) The SEISM Collaboration 20 20 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  21. ECR (60 GHz) Source (2) Fully stripped, not efficient! We will check 1+ ions Strip in Linac? Can RFQ/Linac accelerate 1+ ions? 21 21 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  22. Recent Research: 19F(p, 2n)18Ne T. Stora, P. Valko The ne beam needs production of2.0 1013 18Ne/s Theoretically possible with 10 mA 70 MeV protons on NaF We need measurements of the cross section 19F(p, 2n)18Ne ! Neutrino Summer School 2010: Beta Beams, Elena Wildner

  23. Options for production Courtesy T. Stora, P Valko Needs some optimization R & D !!! Possible Challenging 8Li can be produced by similar methods as 6He in good amounts Neutrino Summer School 2010: Beta Beams, Elena Wildner

  24. Recent Results for Production of 6He • 5 1013 6He/s 600kW, 40 MeV deuteron beam • 5 10136He/s 200kW, 2 GeV proton beam (ISOLDE 2008) Can be used also for production of 8Li N. Thiolliere et al., EURISOL-DS M. Hass et al., J. Phys. G 35, 014042 (2008); T. Hirsh et al., PoS (Nufact08)090 Aimed: He 2.9 1018 (2.0 1013/s) T. Stora et al., EURISOL-DS, TN03-25-2006-0003 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  25. Problems with radiation • Radioprotection • Protection of the population • Rules and recommendations • Residual Ambient Dose Equivalent Rate at 1 m distance from the beam line (mSv h-1) • Annual Effective Dose to the Reference Population (mSv) • Damage to materials (rust, plastics) • Superconducting magnets • Cables cannot stand deposited heat • Cryogenic system cannot cool the magnet if too much heat is deposited from the decay products 25 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  26. Radioprotection Not a show stopper Stefania Trovati, Matteo Magistris, CERN CERN-EN-Note-2009-007 STI EURISOL-DS/TASK2/TN-02-25-2009-0048 Yacin Kadi et al. , CERN 26 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  27. Activation and coil damage in the PS M. Kirk et. al GSI The coils could support 60 years operation with a EURISOL type beta-beam 27 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  28. Bunched beams in synchrotrons Accelerating gap with the RF voltage V t This corresponds to the electical field the reference particle sees An early particle gets less energy increase p –pref Grouping of particles (no acceleration) RF phase Group of Particles (“bunch”) “Bucket”: Energy/phase condition for stability 28 28 28 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  29. Duty factor and RF Cavities 1014 ions, 0.5% duty (supression) factor for background suppression !!! .... Erk Jensen, CERN 20 bunches, 5.2 ns long, distance 23*4 nanosseconds filling 1/11 of the Decay Ring, repeated every 23 microseconds 29 29 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  30. Superconducting magnets Workingtemperature 1.9 K ! Coldest spot i the universe... The LHC Dipole, 8.4 T • “Two in one” construction for LHC, for beta beams we need only one aperture, but larger! 30 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  31. High g and decay-ring size, 6He Examples!!! Example : Neutrino oscillation physics with a higher gb-beam, arXiv:hep-ph/0312068 J. Burguet-Castell, D. Casper, J.J. Gomez-Cadenas, P.Hernandez, F.Sanchez 31 31 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  32. Particle deposition in Decay Ring Momentum collimation Arc Straight section Arc Straight section Cosq design open midplane magnet J. Bruer, E. Todesco, E. Wildner, CERN Superconducting Magnet: Manageable (7 T operational) with Nb -Ti at 1.9 K Momentum collimation (study ongoing): Very high challenge! 32 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  33. High Intensities,long&hardwork! New machines can be designed for high intensity Our old machines have limitations 33 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  34. Other Beta Beams • Most present work on beta beams is going on within • EUROnu • Other laboratories have also worked on beta beams • INO, India (S. Choubey) • Fermilab, USA (A. Janson) • IPN, France (C.Volpe) • University of Valencia, Spain (J. Barnabeu) • … 34 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  35. The beta-beam in EUROnu DS • The study is focused on production issues for 8Li and 8B • Production ring • Production and beam cooling are simulated • Collection of the produced ions, release efficiencies and cross sections for the reactions (UCL, INFN) • Sources ECR(LPSC, GHMFL) • Supersonic Gas injector, collaboration GSI • CERN Complex • Research on 18Ne and experiments for 6He give very good results • Collective effects, all ions (CERN, CEA) • Costing and comparison with other neutrino facilities • Synergy Beta Beams/Superbeams 35 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  36. Where are the project risks • Production of the neutrino emitters, 18Ne and 8B • We can produce 18Ne ions (at least on paper) • The production ring proposal is not feasible for the time being • Other methods for B production ? • CERN Complex • We need to check that we can accelerate the high intensity ion beams • High-Q ions need higher intensities in the decay ring (longer baselines) • Can beta beams compete with neutrino factories? • Beta beams are relatively straight forward • Important: we need a suitable detector !!! Funding? • We are very few collaborators: join us! We know the technological challenges and we can calculate the limits 36 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  37. Beta Beams potential 37 37 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  38. Combining energies from BB and EC • Sensitivity to θ13 and δ (CERN to Gran Sasso or Canfranc ) difficult to make, space charge ? J. Bernabeu, C. Espinosa, C. Orme, S. Palomares-Ruiz and S. Pascoli based on JHEP 0906:040, 2009 38 Neutrino Summer School 2010: Beta Beams, Elena Wildner

  39. Summary • The interest for beta beams is world-wide • There is a design-study ongoing (using CERN infrastructures) • The beta beam baseline: 6He and 18Ne (CERN Frejus) • Research for higher-Q ions (Longer baseline ~ 700 km) • Challenges: • High intensity, collimation for bkgsuppression, ion production • Protect against high radiation • We need your help, join the team! 39 Neutrino Summer School 2010: Beta Beams, Elena Wildner

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