RAL 27 April 2006The beta-beam task, EURISOL1 Status of the beta-beam study Mats Lindroos on behalf of the EURISOL beta-beam task

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 2 Outline The beta-beam Progress on a conceptual design EURISOL beta-beam facility Challenges for the beta-beam Conclusions

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 3 The EURISOL beta-beam facility!

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 4 Beta-beam R&D The EURISOL Project Design of an ISOL type (nuclear physics) facility. Performance three orders of magnitude above existing facilities. A first feasibility / conceptual design study was done within FP5. Strong synergies with the low-energy part of the beta-beam: Ion production (proton driver, high power targets). Beam preparation (cleaning, ionization, bunching). First stage acceleration (post accelerator ~100 MeV/u). Radiation protection and safety issues. Subtasks within beta-beam task ST 1: Design of the low-energy ring(s). ST 2: Ion acceleration in PS/SPS and required upgrades of the existing machines including new designs to eventually replace PS/SPS. ST 3: Design of the high-energy decay ring. Around 38 (13 from EU) man-years for beta-beam R&D over next 4 years (only within beta-beam task, not including linked tasks).

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 5 Design study objectives Establish the limits of the first study based on existing CERN accelerators (PS and SPS) Freeze target values for annual rate at the EURISOL beta-beam facility Close cooperation with neutrino physics community Freeze a baseline for the EURISOL beta-beam facility Produce a Conceptual Design Report (CDR) for the EURISOL beta-beam facility Produce a first cost estimate for the facility

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 6 Challenges for the study Production Charge state distribution after ECR source The self-imposed requirement to re-use a maximum of existing infrastructure Cycling time, aperture limitations etc. The small duty factor The activation from decay losses The high intensity ion bunches in the accelerator chain and decay ring

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 7 Intensity distribution during acceleration 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 Bunch 20 th 15 th 10 th 5th 1st total

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 8 Power losses - comparison Nucleon losses compared PS and SPS comparable for CNGS and bb operation PS exposed to highest power losses P loss /l [ions]Beta-beam CNGS 6 He 18 Ne RCS PS SPS Power loss per unit circumference of a machine

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 9 Dynamic vacuum Decay losses cause degradation of the vacuum due to desorption from the vacuum chamber The current baseline includes the PS, which does not have an optimized lattice for unstable ion transport and has no collimation system The dynamic vacuum degrades to Pa in steady state ( 6 He) An optimized lattice with collimation system improves the situation by two orders of magnitude P. Spiller et al., GSI

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 10 Merging Achieving >90% merging efficiency of injected particles Some ions are already collimated before having been stacked for 15 (20) merging cycles Ions stored /ions injected t [s] Ions stored /ions injected t [s] 6He 18Ne S. Hancock, CERN

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 11 Injected/merged collimated decayed Decay ring - Momentum collimation After 15 (20) merges 50% (70%) of the injected 6He (18Ne) ions are pushed outside the acceptance limits. Momentum collimation required. Dispersion region; multi stage collimation system Space required: placed in “unused” straight section Collimation power corresponds to 150 kW average to MW peak level during the bunch compression process compression process lasts a few hundred milliseconds A. Chance et al., Saclay He6Ne18LHC p+LHC Pb  T/ion (GeV) τ repetition (s)63.610h Number of stored ions Stored beam energy (MJ) x 3622 x 3.81

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 12 aperture [cm] Power loss [W/m] Decay ring - Decay losses Decay products originating 1) from straight section 2) in arcs 1) are extracted at the first dipole in the arc, sent to dump 2) Arc lattice optimized for absorption of decay products To accommodate either ion species, the half-aperture has to be very large (~ 8cm for the SC dipoles). Absorbers take major part of decay losses ion arcs. About 60 W each SC dipoles still have to stand <10 W/m. A. Chance et al., Saclay

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 13 Production Major challenge for 18 Ne Workshop at LLN for production, ionization and bunching this summer New production method proposed by C. Rubbia!

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 14 Production ring with ionization cooling (C. Rubbia, A.Ferrari, Y.Kadi and V. Vlachoudis)

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 15 Ionization cooling

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 16 Using existing PS and SPS, version 2 Space charge limitations at the “right flux” Space charge tune shift Note that for LHC the corresponding values are and Transverse emittance normalized to PS acceptance at injection for an annual rate of (anti-) neutrinos

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 17 The slow cycling time. What can we do? Production PS SPS Decay ring Ramp time PS Time (s)0 8 Wasted time? Ramp time SPS Reset time SPS

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 18 Accumulation at 400 MeV/u T 1/2 =1.67 s T 1/2 =17 s T 1/2 =0.67 s

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 19 Stacking Multiturn injection with electron cooling

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, Dy Partly stripped ions: The loss due to stripping smaller than 5% per minute in the decay ring Possible to produce Dy atoms/second (1+) with 50 microAmps proton beam with existing technology (TRIUMF) An annual rate of decays along one straight section seems as a realistic target value for a design study Beyond EURISOL DS: Who will do the design? Is 150 Dy the best isotope?

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 21 Long half life – high intensities At a rate of neutrinos using the EURISOL beta-beam facility:

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 22 Gamma and decay-ring size, 6 He GammaRigidity [Tm] Ring length T=5 T f=0.36 Dipole Field rho=300 m Length=6885m Civil engineering Magnet R&D New SPS

RAL 27 April 2006 The beta-beam task, EURISOL Beta-beam requirements, 23 In 2008 we should know The EURISOL design study will with the very limited resources available give us: A feasibility study of the CERN-Frejus baseline A first idea of the total cost An idea of how we can go beyond the baseline Resources and time required for R&D Focus of the R&D effort Production, Magnets etc.