AB seminarBENE beta-beam network The Beta-beam Mats Lindroos on behalf of the The BENE beta-beam network

AB seminarBENE beta-beam network 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

AB seminarBENE beta-beam network 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

AB seminarBENE beta-beam network Outline Neutrino oscillations The beta-beam –Overview –The CERN base line scenario –The Moriond workshop The super beam Conclusions

AB seminarBENE beta-beam network Neutrinos A mass less particle predicted by Pauli to explain the shape of the beta spectrum Exists in at least three flavors (e, ,  ) 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

AB seminarBENE beta-beam network Neutrino oscillations Three neutrino mass states (1,2,3) and three neutrino flavors (e, ,  )  23  (atmospheric) = 45 0,  12  (solar) = 30 0,  13  (Chooz) < 13 0 Unknown or poorly known even after approved program:  13, phase , sign of  m 13 2 OR?  m 2 23 = eV 2  m 2 12 = eV 2        m 2 23 = eV 2 A. Blondel

AB seminarBENE beta-beam network 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

AB seminarBENE beta-beam network CERN:  -beam baseline scenario PS Decay Ring ISOL target & Ion source SPL Cyclotrons, linac or FFAG Decay ring Brho = 1500 Tm B = 5 T L ss = 2500 m SPS ECR Rapid cycling synchrotron Nuclear Physics

AB seminarBENE beta-beam network Desired beam parameters in the decay ring 18 Neon 10+ –Intensity: 4.5x10 12 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 6 He is the more demanding ion and considered further on. 6 Helium 2+ –Intensity: 1.0x10 14 ions –Energy: 139 GeV/u –Rel. gamma: 150 –Rigidity: 1500 Tm

AB seminarBENE beta-beam network 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 PSSPS Decay ring

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

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

AB seminarBENE beta-beam network Scenario 1 Spallation of close-by target nuclides: 18,19 Ne from MgO and 34,35 Ar in CaO –Production rate for 18 Ne is 1x10 12 s -1 (with 2.2 GeV 100  A proton beam, cross-sections of some mb and a 1 m long oxide target of 10% theoretical density) – 19 Ne can be produced with one order of magnitude higher intensity but the half life is 17 seconds! Scenario 2 alternatively use ( ,n) and ( 3 He,n) reactions: 12 C( 3,4 He,n) 14,15 O, 16 O( 3,4 He,n) 18,19 Ne, 32 S( 3,4 He,n) 34,35 Ar –Intense 3,4 He beams of mA 50 MeV are required Production of  + emitters

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

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

AB seminarBENE beta-beam network 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 PSSPS Decay ring

AB seminarBENE beta-beam network 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 PSSPS Decay ring

AB seminarBENE beta-beam network Overview: Accumulation Sequential filling of 16 buckets in the PS from the storage ring

AB seminarBENE beta-beam network PS Accumulation of 16 bunches at 300 MeV/u Acceleration to  =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

AB seminarBENE beta-beam network SPS Overview: PS to SPS Merging in PS to 8 buckets Blow-up before transfer to manage space charge limit in SPS PS SPS PS

AB seminarBENE beta-beam network SPS Objective: Acceleration of 8 bunches of 6 He(2+) to  =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

AB seminarBENE beta-beam network 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 PSSPS Decay ring

AB seminarBENE beta-beam network 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  s). –Maximum flexibility for adjusting the relative distance bunch to stack on ns time scale.

AB seminarBENE beta-beam network SPS Overview: Decay ring Ejection to matched dispersion trajectory Asymmetric bunch merging SPS

AB seminarBENE beta-beam network Horizontal aperture layout Assumed machine and beam parameters: –Dispersion:D hor = 10 m –Beta-function:  hor = 20 √m –Moment. spread stack:  p/p = ±1.0x10 -3 (full) –Moment. spread bunch:  p/p = ± 2.0x10 -4 (full) –Emit. (stack, bunch):  geom = 0.6  m Septum & alignment 10 mm Stack: ± 10mm momentum ± 4 mm emittance Beam: ± 2 mm momentum ± 4 mm emittance Required separation: 30 mm, corresponds to 3x10 -3 off-momentum. Required bump: 22 mm Central orbit undisplaced M. Benedikt

AB seminarBENE beta-beam network Injection to decay ring M. Benedikt

AB seminarBENE beta-beam network Asymmetric bunch merging S. Hancock

AB seminarBENE beta-beam network 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  -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.

AB seminarBENE beta-beam network Decay losses Acceleration losses: 6 He (T 1/2 =0.8 s) 18 Ne (T 1/2 =1.67 s) Accumulation<47 mW/m<2.9 mW/m PS1.2 W/m 90 mW/m SPS0.41 W/m32 mW/m Decay ring8.9 W/m0.6 W/m A. Jansson

AB seminarBENE beta-beam network 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.

AB seminarBENE beta-beam network 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

AB seminarBENE beta-beam network 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 Shielding Tunnel Arc cross-section CERN Cricket Club

AB seminarBENE beta-beam network Intensities: 6 He From ECR source: 2.0x10 13 ions per second Storage ring: 1.0x10 12 ions per bunch Fast cycling synch:1.0x10 12 ion per bunch PS after acceleration: 1.0x10 13 ions per batch SPS after acceleration:0.9x10 13 ions per batch Decay ring: 2.0x10 14 ions in four 10 ns long bunch –Only  -decay losses accounted for, efficiency <50%

AB seminarBENE beta-beam network Intensities: 18 Ne From ECR source: 0.8x10 11 ions per second Storage ring: 4.1x10 10 ions per bunch Fast cycling synch:4.1x10 10 ion per bunch PS after acceleration: 5.2x10 11 ions per batch SPS after acceleration:4.9x10 11 ions per batch Decay ring: 9.1x10 12 ions in four 10 ns long bunch –Only  -decay losses accounted for, efficiency <50%

AB seminarBENE beta-beam network 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)

AB seminarBENE beta-beam network Ne and He in decay ring simultaneously Enormous “gain” in counting time –Years! Requiring  =150 for He will at equal rigidity result in a  =250 for Ne –Physics? –Detector simulation should give “best” compromise Requiring equal revolution time will result in a  R of 20 mm (R 0 =1090 m) –Manageable?

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

AB seminarBENE beta-beam network CERN to FREJUS Geneve Italy 130km 40kt  400kt CERN CERN 2.2GeV, 50Hz, 2.3x10 14 p /pulse  4MW Now under R&D phase

AB seminarBENE beta-beam network The Super Beam

AB seminarBENE beta-beam network HERE : 250 MeV NEUTRINOS

AB seminarBENE beta-beam network Water Cherenkow Super Kamiokande MultiUSER detector: Astrophysics, Beta-beam, Super Beam, Proton Decay

AB seminarBENE beta-beam network Combination of beta beam with low energy super beam Unique to CERN: combines CP and T violation tests e   (  +)    e (  + ) e   (  -)    e (  - ) A. Blondel CP T T

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

AB seminarBENE beta-beam network Physics reach M. Mezzetto

AB seminarBENE beta-beam network Superbeam & Beta Beam cost estimates (NUFACT02)

AB seminarBENE beta-beam network 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

AB seminarBENE beta-beam network Open questions… …among them Target (area) design –EURISOL study (Design study in 6 th 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

AB seminarBENE beta-beam network 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!