Beta-beam design status and technical challenges ahead Elena Wildner, CERN European Strategy for Future Neutrino Physics, CERN 1 -3 Oct 2009 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 1
Outline n n n 02/10/09 Beta Beam Concepts A Beta Beam Scenario Ion Production Other Challenges Other Beta Beam Scenarios Summary European Strategy for Future Neutrino Physics, Elena Wildner 2
Beta-beams, recall Aim: production of (anti-)neutrino beams from the beta decay of radioactive ions circulating in a storage ring n Similar concept to the neutrino factory, but parent particle is a beta-active isotope instead of a muon. Beta-decay at rest n n n Accelerate parent ion to relativistic gmax n n n Boosted neutrino energy spectrum: En 2 g. Q Forward focusing of neutrinos: 1/g Pure electron (anti-)neutrino beam! n n-spectrum well known from the electron spectrum Reaction energy Q typically of a few Me. V E 0 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 n n Primarily neutrino oscillation physics and CP-violation (high energy) Cross-sections of neutrino-nucleus interaction (low energy) 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 3
Choice of radioactive ion species n Beta-active isotopes n n n Production rates Life time Dangerous rest products Reactivity (Noble gases are good) n n n 6 He and 18 Ne 1 ms – 1 s 1 – 60 s Reasonable lifetime at rest n n t 1/2 at rest (ground state) 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 8 Li and 8 B Nu. Base Low Z preferred n n n Minimize ratio of accelerated mass/charges per neutrino produced One ion produces one neutrino. Reduce space charge problems 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 4
Some scaling n Accelerators can accelerate ions up to Z/A × the proton energy. n L ~ <En > / Dm 2 ~ g. Q , Flux ~ L− 2 => Flux ~ Q − 2 n Cross section ~ <En > ~ g Q n n 02/10/09 Merit factor for an experiment at the atmospheric oscillation maximum: M= g /Q Decay ring length scales ~ g (ion lifetime) European Strategy for Future Neutrino Physics, Elena Wildner 5
Beta beam to different baselines 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 6
The EURISOL scenario(*) boundaries n n n Based on CERN boundaries Ion choice: 6 He and 18 Ne Based on existing technology and machines n n n EURISOL scenario 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 n n SPS allows maximum of 150 (6 He) or 250 (18 Ne) Gamma choice optimized for physics reach n Opportunity to share a Mton Water Cherenkov detector with a CERN super-beam, proton decay studies and a neutrino observatory n Achieve an annual neutrino rate of n n n top-down approach 2. 9*1018 anti-neutrinos from 6 He 1. 1 1018 neutrinos from 18 Ne The EURISOL scenario will serve as reference for further studies and developments: Within Euron we study 8 Li and 8 B (*) 02/10/09 European Strategy for Future Neutrino Physics, FP 6 "Structuring the European Research Area" programme Elena Wildner (CARE, contract number RII 3 -CT-2003 -506395) 7
The EURISOL scenario Decay ring Br = 1500 Tm Aimed: He 2. 9 1018 ( 2. 0 1013/s after target) Ne 1. 1 1018 ( 2. 0 1013/s after target) B = ~6 T C = ~6900 m Lss= ~2500 m 6 He: 18 Ne: g = 100 93 Ge. V 0. 4 Ge. V 8. 7 Ge. V 1. 7 Ge. V Design report 2009 European Strategy for Future Neutrino Physics, Elena Wildner 8
Intensity evolution during acceleration Bunch 20 th total 15 th 10 th 5 th 1 st Cycle optimized for neutrino rate towards the detector 30% of first 6 He bunch injected are reaching decay ring Overall only 50% (6 He) and 80% (18 Ne) reach decay ring Normalization Single bunch intensity to maximum/bunch Total intensity to total number accumulated in RCS European Strategy for Future Neutrino Physics, Elena Wildner 9
Radioprotection Residual Ambient Dose Equivalent Rate at 1 m distance from the beam line (m. Sv h -1) RCS (quad - 18 Ne) PS (dip - 6 He) SPS DR (arc - 18 Ne) 1 hour 15 10 - 5. 4 1 day 3 6 - 3. 6 1 week 2 2 - 1. 4 Not a show stopper Annual Effective Dose to the Reference Population (m. Sv) RCS PS SPS DR 0. 67 0. 64 - 5. 6 (only decay losses) Stefania Trovati, Matteo Magistris, CERN-EN-Note-2009 -007 STI EURISOL-DS/TASK 2/TN-0225 -2009 -0048 Yacin Kadi et al. , CERN 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 10
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 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 11
Particle turnover in decay ring p-collimation Arc ion ect ht s ses aig y los Str deca injection merging Momentum collimation Arc Straight section n Momentum collimation (study ongoing): ~5*1012 6 He ions to be collimated per cycle Decay: ~5*1012 6 Li ions to be removed per cycle per meter n Dump at the end of the straight section will receive 30 k. W n Dipoles in collimation section receive between 1 and 10 k. W (masks). 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 12
Duty factor and Cavities for He/Ne 1014 ions, 0. 5% duty (supression) factor for background suppression !!!. . 20 bunches, 5. 2 ns long, distance 23*4 nanosseconds filling 1/11 of the Decay Ring, repeated every 23 microseconds Erk Jensen, CERN 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 13
Open Midplane Dipole for Decay Ring Cos design open midplane magnet Manageable (7 T operational) with Nb -Ti at 1. 9 K Aluminum spacers possible on midplane to retain forces: gives transparency to the decay products Special cooling and radiation dumps may be needed inside yoke. J. Bruer, E. Todesco, E. Wildner, CERN 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 14
Open mid-plane Quadrupole Parametric Approach!! Acknowledgments (magnet design): F Borgnolutti, E. Todesco (CERN) Opening angle 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 15
Options for production n ISOL method at 1 -2 Ge. V (200 k. W) n n Aimed: He 2. 9 1018 (2. 0 1013/s) Ne 1. 1 1018 (2. 0 1013/s) Direct production n n 2 1013 6 He per second <8 1011 18 Ne per second Studied within EURISOL >1 1013 (? ) 6 He per second 1 1013 18 Ne per second Studied at LLN, Soreq, WI and GANIL Production ring n n n 1014 8 Li See talks by T. Stora and S. Mitrofanov (? ) per second >1013 (? ) 8 B per second Chemistry Difficult Studied Within EUROn N. B. Nuclear Physics has limited interest in those elements => Production rates not pushed! Try to get ressources to persue ideas how to produce Ne! 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 16
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 A 562(2006)591 Supersonic gas jet target, stripper and absorber 7 Li(d, p)8 Li 7 Li 6 Li(3 He, n)8 B 6 Li From C. Rubbia, et al. in NIM A 568 (2006) 475– 487 Studied within Euron FP 7 (*) European Strategy for Future Neutrino Physics, (*) FP 7 “Design Studies” (Research Infrastructures) EUROnu Elena Wildner (Grant agreement no. : 212372) 17
Beta Beam scenario EUROnu, FP 7 Ion Linac 20 Me. V Ion production PR n-beam to experiment 8 B/8 Li Decay ring ISOL target, Collection Br ~ 500 Tm Existing!!! 60 GHz pulsed ECR Linac, 0. 4 Ge. V PS 2 31 Ge. V SPS 92 Ge. V Neutrino Source Decay Ring B = ~6 T C = ~6900 m Lss= ~2500 m 8 Li: 18 B: g = 100 . RCS, 5 Ge. V Detector Gran Sasso (~ 5 times higher Q) 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 18
The beta-beam in EURONU DS (I) n The study will focus on production issues for 8 Li and 8 B n n 8 B is highly reactive and has never been produced as an ISOL beam Production ring: enhanced direct production n n n Ring lattice design (CERN) Ionization Cooling (CERN +) Collection of the produced ions, release efficiencies and cross sections for the reactions (UCL, INFN, ANL) Sources ECR (LPSC, GHMFL) Supersonic Gas injector (PPPL + ? ) CERN Complex n n n 02/10/09 All machines to be simulated with B and Li (CERN, CEA) PS 2 presently under design (requirements for beta beams) Multiple Charge State Linacs (P Ostroumov, ANL) European Strategy for Future Neutrino Physics, Elena Wildner 19
Associated partners in EURONU DS 3 -Flavor Oscillation needs two significantly different baselines Possible realization with one to disentangle CP and matter effects detector only (price) nm-beam: SPL: <En> = 260 Me. V Lopt = 134 km CERN – Frejus: 130 km ne-beam: g = 100 Lopt = 130 km g = 500 Lopt = 1000 km CERN – Frejus: 130 km DESY – Frejus: 960 km 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 20
The production Ring: Ion Source for Beta Beams wedged Gas Jet-Target RF Cavity 12 m circumference mirror symmetrical structure 1. 5 T dipoles 5 quadrupole-families Dx = 0 in cavity-section best choice of Dx in target-section depends on wedge angle of the target 02/10/09 Michaela Schaumann , Aachen/CERN, 2009 Jakob Wehner, Aachen/CERN, 2009 Elena Benedetto, CERN, 2009 See Poster session 21
The production ring cooling: review 7 Li 6 Li 7 Li(d, p)8 Li 6 Li(3 He, n)8 B Low-energy Ionization cooling of ions for Beta Beam sources – From C. Rubbia, et al. D. Neuffer (FERMILAB-FN-0808 -APC)in NIM A 568 (2006) 475– 487 Mini-workshop on cooling at Fermilab summer 2009 (David Neuffer ) joining teams from CERN and Fermilab 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 22
Challenge: collection device n A large proportion of beam particles (6 Li) will be scattered into the collection device. n Production of 8 Li and 8 B: 7 Li(d, p) 8 Li and 6 Li(3 He, n) 8 B reactions using low energy and low intensity ~ 1 n. A beams of 6 Li(4 -15 Me. V) and 7 Li(10 -25 Me. V) hitting the deuteron or 3 He target. n Semen Mitrofanov (See next talk) n Thierry Delbar Marc Loiselet n 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 23
Cross section measurements at Laboratori Nazionali di Legnaro M. Mezzetto (INFN-Pd) on behalf of INFN-LNL: M. Cinausero, G. De Angelis, G. Prete First Experiment performed in July 2008 Inverse kinematic reaction: 7 Li + CD 2 target E=25 Me. V Data reduction in progress Future: reduce contamination 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 7 Li 24
ECR 60 GHz Source Courtesy: Thierry Lamy, LPSC n Source Assembly for October 2009 n n n Magnet field measurements at half intensity Tests of source at 28 GHz expected in 2010 Scientific collaboration n ISTC (IAP NN, LPSC, LNCMI, CERN, Istituto di Fisica del Plasma) 490 k€ EU + 225 k€ LPSC Gyrotron manufacturing, 60 GHz plasma and beams developments 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 25
Associates n Weizmann Institue of Science, Revohot q q q n Work Focus q q q n Michael Hass Partners: GANIL and Soreq Collaboration with Aachen (exchange of students) produce light radioactive isotopes also for beta beams secondary neutrons from an intense, 40 Me. V d beam (6 He and 8 Li) and direct production with 3 He or 4 He beams (18 Ne). Use of superconducting LINACs such as SARAF at Soreq (Israel) and the driver for SPIRAL-II (GANIL). Added Value q To produce strong beta beam ion candidates or production methods not in EUROnu Courtesy Micha Hass 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 26
Relaxed Duty Factors for more neutrinos 0. 5% duty factor for background suppression could be relaxed for higher neutrino energies. . . But not enough to profit of Barrier Buckets for B and Li! We need in addition more flux for high-Q ions. Christian Hansen Enrique Fernandez-Martinez See Poster session 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 27
![High g and decay-ring size, 6 He Gamma Rigidity [Tm] Ring length T=5 T](https://present5.com/presentation/255aa59397e528b61b8ac24c4a423e4e/image-28.jpg "High g and decay-ring size, 6 He Gamma Rigidity [Tm] Ring length T=5 T")
High g and decay-ring size, 6 He Gamma Rigidity [Tm] Ring length T=5 T f=0. 36 Dipole Field rho=300 m Length=6885 m 100 150 200 350 500 938 1404 1867 3277 4678 4916 6421 7917 12474 17000 3. 1 4. 7 6. 2 10. 9 15. 6 Magnet R&D Example : Neutrino oscillation physics with a higher g b-beam, ar. Xiv: hep-ph/0312068 J. Burguet-Castell, D. Casper, J. J. Gomez-Cadenas, P. Hernandez, F. Sanchez 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 28
Beta Beams at Fermilab 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 29
Optimized Two-Baseline Beta Beam Courtesy: Sandhya Choubey n Beta Beam Concepts n Beta Beam Scenarios n Ion Production 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 30
Low energy Beta Beams Christina Volpe: A proposal to establish a facility for the production of intense and pure low energy neutrino beams (100 Me. V). BASELINE SPS To off axis far detector n storage ring PS n close detector J Phys G 30 (2004) L 1. PHYSICS POTENTIAL n-nucleus cross sections (detector’s response, r-process, 2 b-decay) fundamental interactions studies (Weinberg angle, CVC test, mn) astrophysical applications PHYSICS STUDIED WITHIN THE EURISOL DS (FP 6, 2005 -2009) 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 31
The virtues of combining energies from BB and EC • Sensitivity to θ 13 and δ (CERN to Gran Sasso or Canfranc ) Long lifetime, difficult to make, space charge ? J. Bernabeu, C. Espinosa, C. Orme, S. Palomares-Ruiz and S. Pascoli based on JHEP 0906: 040, 2009 32
Summary (i) n The EURISOL beta-beam conceptual design report will be presented during 2009 (6 He and 18 Ne , gamma 100) n First coherent study of a beta-beam facility n Top down approach n 18 Ne shortfall as of today n Duty Factors are challenging: Collimation and RF in Decay Ring 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 33
Summary (ii) n A beta-beam facility using 8 Li and 8 B (EUROnu) (gamma 100) n n n n 02/10/09 Experience from EURISOL Production issues (pay attention to 18 Ne) Optimize chain Revisit Duty Factors, RF and bunch structures Acceptance of PS 2 (Complete) simulation of beta beam complex Costing First results will come from Euronu DS (2008 -2012) European Strategy for Future Neutrino Physics, Elena Wildner 34
Acknowledgements FP 6 "Structuring the European Research Area" programme (CARE, contract number RII 3 -CT-2003 -506395) and FP 7 “Design Studies” (Research Infrastructures) EUROnu (Grant agreement no. : 212372) Particular thanks to M. Benedikt, FP 6 Leader M. Lindroos, A Fabich, S. Hancock M. Mezetto … and all contributing institutes and collaborators 02/10/09 European Strategy for Future Neutrino Physics, Elena Wildner 35
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