Now 2010: Beta Beams, Elena Wildner1 Beta-Beams Elena Wildner, CERN

Now 2010: Beta Beams, Elena Wildner 2 Outline The Beta Beam concept A Beta Beam scenario The challenges Other studies Conclusion 22

Now 2010: Beta Beams, Elena Wildner Beta Beams 3 The aim is to produce (anti-)neutrino beams from the beta decay of radio-active ions circulating in a storage ring with long straight sections (Zuchelli, 2002). Energy of neutrinos Reaction energy Q typically of a few MeV Accelerate ions to relativistic  max Boosted neutrino energy spectrum: E   2  Q Forward focusing of neutrinos:   1/  Two different parent isotopes to produce and anti- respectively

4 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 NuBase t 1/2 at rest (ground state) 1 – 60 s 1ms – 1s 6He and 18Ne 8Li and 8B Now 2010: Beta Beams, Elena Wildner

5 High Energy Beta beam Design Studies Eurisol design Study, EC FP6, He and 19Ne, ISOL Baseline: Frejus Gamma: 100, Low-Q ~ 3.5 MeV 18Ne production, ISOL, 20 times below requirements No beam stability studies Decay Ring RF HW not studied Low energy part of acceleration not studied EUROnu Project, EC FP7, Li and 8B, Production Ring, Ion collection Baseline: Canfranc / Gran Sasso Gamma: 100, High-Q ~ 16 MeV 19Ne production intensified, experiments for 6He Low energy part of acceleration studied Intense beam stability studied (Collective Effects) Decay Ring HW for RF System Studied Costing

Now 2010: Beta Beams, Elena Wildner 6 6 Some scaling, high Q or high  Accelerators can accelerate ions up to Z/A × the proton energy. L ~ /  m 2 ~  Q, Flux ~ L −2 => Flux ~ Q −2 Cross section ~ ~  Q Merit factor (Flux * Cross-section) for an experiment at the atmospheric oscillation maximum: M=  Q Remember: ion lifetime ~ , 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.

Now 2010: Beta Beams, Elena Wildner 7 7 Beta beam to different baselines

Neutrino 2010 (Athens): Beta Beams, Elena Wildner 88 The EURISOL scenario boundaries Based on CERN boundaries Ion choice: 6 He and 18 Ne 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 ( 6 He) or 250 ( 18 Ne) 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*10 18 anti-neutrinos from 6 He neutrinos from 18 Ne The EURISOL scenario will serve as reference for further studies and developments: Within Euro we will study 8 Li and 8 B EURISOL scenario top-down approach 8 (*) 8 Now 2010: Beta Beams, Elena Wildner FP6 “Research Infrastructure Action - Structuring the European Research Area” EURISOL DS Project Contract no RIDS

Beta Beam scenario 6He/18Ne Neutrin o Source Decay Ring ISOL target Decay ring B  ~ 500 Tm B = ~ 6 T C = ~ 6900 m L ss = ~ 2500 m 6 He:  = Ne:  = 100 SPS RCS -beam to Frejus Linac, 100 MeV/n 60 GHz pulsed ECR Existing!!! 450 GeV p Ion production 6He/18Ne PS Super Proton Linac Now 2010: Beta Beams, Elena Wildner 9

Beta Beam scenario 6He/18Ne Neutrin o Source Decay Ring ISOL target Decay ring B  ~ 500 Tm B = ~ 6 T C = ~ 6900 m L ss = ~ 2500 m 6 He:  = Ne:  = 100 SPS RCS -beam to Frejus Linac, 100 MeV/n 60 GHz pulsed ECR Existing!!! 450 GeV p Ion production 6He/18Ne PS Super Proton Linac 18Ne Isotopes is not possible to produce with ISOL technology: New Ideas are needed!!! Now 2010: Beta Beams, Elena Wildner 10 DR Design by A. Chance, CEA RCS Design by A. Lachaize, CNRS

Now 2010: Beta Beams, Elena Wildner 11 European Strategy for Future Neutrino Physics, Elena Wildner 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 Studied within FP7 ”Euro ” (*) FP7 “Design Studies” (Research Infrastructures) EUROnu (Grant agreement no.: ) (*) Supersonic gas jet target, stripper and absorber Ring lattice, target modeling and cooling simulations: E Benedetto, M. Schaumann, J. Wehner

12 Beta Beam scenario 8Li/8B Neutrin o Source Decay Ring ISOL target, Collection Decay ring B  ~ 500 Tm B = ~6 T C = ~6900 m L ss = ~2500 m 8 Li:  = B:  = 100 SPS RCS, 1.7 GeV -beam to GranSasso/Canfranc Linac, 100 MeV 60 GHz pulsed ECR Existing!!! 280 GeV Ion production PR Ion Linac 25 MeV, 7 Li and 6 Li 8B/8Li PS Now 2010: Beta Beams, Elena Wildner

Now 2010: Beta Beams, Elena Wildner 13 PR: Gas Jet Targets and Cooling (GSI) We need cm -2 !!

Now 2010: Beta Beams, Elena Wildner 14 Challenge: collection device Status: The collection device is under test, results expected end summer 2010 for 8Li. Tests for 8B will follow. Semen Mitrofanov Thierry Delbar Marc Loiselet

Now 2010: Beta Beams, Elena Wildner X-sections, Energies and Angles, Li and B 15 8B production experiments are being planned at Legnaro (2010) Inverse kinematic reaction proposed: (heavy ion beam on light target): 7 Li + CD 2 target E beam =25 MeV Due to problems with gas jet target we will start simulations with normal kinematics. Liquid target challenges: energy deposition, collection angles, beam cooling… 15 INFN-LNL: M. Cinausero, G. De Angelis, G. Prete, E Vardaci

Now 2010: Beta Beams, Elena Wildner 16 ECR (60 GHz) Source (1) 16 The SEISM Collaboration: Challenges: Produce stripped ions (more difficult for high A ions) Adapted pulse length Optimize for further acceleration: RFQ & Linac The source is developed for He, Ne, B and Li New stripping conditions: fully stripped-> 1+ ! Efficiency of source: 50% ? Need margins ? Status: Magnetic tests scheduled for mid GHz gyrotron for mid 2011

Now 2010: Beta Beams, Elena Wildner 17 Recent Research: 19 F(p, 2n) 18 Ne T. Stora, P. Valko The  e beam needs production of Ne/s Theoretically possible with 10 mA 70 MeV protons on NaF We need measurements of the cross section 19 F(p, 2n) 18 Ne !

Now 2010: Beta Beams, Elena Wildner Options for production TypeAcceleratorBeamI beam mA E beam MeV P beam kW TargetIsotopeFlux S -1 Ok? ISOL & n-converter SPLp W/BeO6He ISOL & n-converter Saraf/GANILd C/BeO6He ISOLLinac 4p F Molten NaF loop 18Ne ISOLCyclo/Linacp F Molten NaF loop 18Ne ISOLLinacX13He> MgO 80 cm disk 18Ne P-RingLinacX27Li d8Li? P-RingLinacX26Li He8B? Experimentally OK On paper may be OK Not OK yet Possible Challenging Courtesy T. Stora, P Valko R & D !!! Needs some optimization 8Li can be produced by similar methods as 6He in good amounts

Now 2010: Beta Beams, Elena Wildner 19 Recent Results for Production of 6 He He/s 600kW, 40 MeV deuteron beam He/s 200kW, 2 GeV proton beam (ISOLDE 2008) Can be used also for production of 8Li M. Hass et al., J. Phys. G 35, (2008); T. Hirsh et al., PoS (Nufact08)090 N. Thiolliere et al., EURISOL-DS T. Stora et al., EURISOL-DS, TN Aimed: He ( /s)

Now 2010: Beta Beams, Elena Wildner 20 Radioprotection 20 Residual Ambient Dose Equivalent Rate at 1 m distance from the beam line (mSv h -1 ) RCS (quad - 18 Ne) PS (dip - 6 He) SPSDR (arc - 18 Ne) 1 hour day week Annual Effective Dose to the Reference Population (  Sv) RCSPSSPSDR (only decay losses) Stefania Trovati, Matteo Magistris, CERN CERN-EN-Note STI EURISOL-DS/TASK2/TN Yacin Kadi et al., CERN

Now 2010: Beta Beams, Elena Wildner 21 Activation and coil damage in the PS M. Kirk et. al GSI 21 The coils could support 60 years operation with a EURISOL type beta-beam

Now 2010: Beta Beams, Elena Wildner 22 The need for duty factors 22 E. Fernandez, C. Hansen B and Li can be relaxed a factor 2

Now 2010: Beta Beams, Elena Wildner 23 More challenges: Duty factor and RF bunches, 5.2 ns long, distance 23*4 nanosseconds filling 1/11 of the Decay Ring, repeated every 23 microseconds ions, 0.5% duty (supression) factor for atm. background reduction!!! 23 Erk Jensen, CERN

Now 2010: Beta Beams, Elena Wildner 24 Hardware challenge: RF Cavities bunches, 5.2 ns long, distance 23*4 nanosseconds filling 1/11 of the Decay Ring, repeated every 23 microseconds ions, 0.5% duty (supression) factor for background suppression !!! 24 Graeme Burt, STFC Collaboration Cockroft Institute (*) started (*) Associated Institue to EUROnu Beta Beams

Now 2010: Beta Beams, Elena Wildner 25 Energy deposition in Decay Ring 25 Cos  design open midplane magnet Superconducting Magnet: Manageable (7 T operational) with Nb -Ti at 1.9 K Higher fields will be studied! New magnet design needs to be shielded! J. Bruer, E. Todesco, E. Wildner, CERN Straight section Arc Momentum collimation Momentum collimation (only preliminary studies): Challenging!

Now 2010: Beta Beams, Elena Wildner 26 High Intensities, research and hard work! 26

Now 2010: Beta Beams, Elena Wildner 27 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)  …

Now 2010: Beta Beams, Elena Wildner 28 Low energy Beta Beams 28 Christina Volpe: A proposal to establish a facility for the production of intense and pure low energy neutrino beams. J Phys G 30 (2004) L1. PS SPS storage ring BASELINE close detector PHYSICS STUDIED WITHIN THE EURISOL DS (FP6, ) To off axis far detector

Now 2010: Beta Beams, Elena Wildner 29 Where are the project risks Production of ions the (anti-) neutrino emitters Good news: He (exp) and Ne (paper) can be produced! The production ring proposal is not feasible for the time being Other methods for B production ? CERN Complex Can we accelerate the high intensity ion beams (all isotopes)? High-Q ions need even higher intensities in the machines Can beta beams compete with neutrino factories? Cost and Physics reach to evaluate Important: we need a suitable detector !!! Funding We do not have the manpower needed to conclude at the end of the EUROnu project 29

30 Beta Beam: potential Now 2010: Beta Beams, Elena Wildner Plots from M. Mezetto

Now 2010: Beta Beams, Elena Wildner 31 Summary EUROnu project ongoing (use CERN infrastructures) Still 2 years funding The beta beam baseline: 6He and 18Ne (CERN Frejus) Research for higher-Q ions (Longer baseline ~ 700 km) Challenges: High intensity, short bunches for bkg suppression Protection against high radiation Costing is now an important issue 31

Now 2010: Beta Beams, Elena Wildner 32 Acknowledgements 32

Now 2010: Beta Beams, Elena Wildner 33 High  and decay-ring size, 6 He GammaRigidity [Tm] Ring length T=5 T f=0.36 Dipole Field rho=300 m Length=6885m Example : Neutrino oscillation physics with a higher   -beam, arXiv:hep-ph/ J. Burguet-Castell, D. Casper, J.J. Gomez-Cadenas, P.Hernandez, F.Sanchez