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

The beta-beam task, EURISOL 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

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

The beta-beam task, EURISOL 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

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

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

Intensity distribution during acceleration Bunch 20th 15th 10th 5th 1st total 30% of first 6He bunch injected are reaching decay ring Overall only 50% (6He) and 80% (18Ne) reach decay ring Normalization Single bunch intensity to maximum/bunch Total intensity to total number accumulated in RCS RAL 27 April 2006 The beta-beam task, EURISOL

Power losses - comparison Power loss per unit circumference of a machine Ploss/l [ions] Beta-beam CNGS 6He 18Ne RCS - 0.17 0.14 PS 3.3 2.2 2.8 SPS 0.25 0.4 Nucleon losses compared PS and SPS comparable for CNGS and bb operation PS exposed to highest power losses RAL 27 April 2006 The beta-beam task, EURISOL

The beta-beam task, EURISOL 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 10-5 Pa in steady state (6He) 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

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

Decay ring - Momentum collimation A. Chance et al., Saclay 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 Injected/merged collimated decayed He6 Ne18 LHC p+ LHC Pb  100 7461 2964 T/ion (GeV) 555 1660 7000 574000 τrepetition (s) 6 3.6 10h Number of stored ions 9.71 1013 7.4 1013 3.2 1014 4 1010 Stored beam energy (MJ) 8.8 19.7 2 x 362 2 x 3.81 RAL 27 April 2006 The beta-beam task, EURISOL

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. aperture [cm] Power loss [W/m] A. Chance et al., Saclay RAL 27 April 2006 The beta-beam task, EURISOL

The beta-beam task, EURISOL Production Major challenge for 18Ne 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

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

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

The beta-beam task, EURISOL Using existing PS and SPS, version 2 Space charge limitations at the “right flux” Transverse emittance normalized to PS acceptance at injection for an annual rate of 1018 (anti-) neutrinos Space charge tune shift Note that for LHC the corresponding values are -0.078 and -0.34 RAL 27 April 2006 The beta-beam task, EURISOL

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

The beta-beam task, EURISOL Accumulation at 400 MeV/u T1/2=1.67 s T1/2=17 s T1/2=0.67 s RAL 27 April 2006 The beta-beam task, EURISOL

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

The beta-beam task, EURISOL 150Dy Partly stripped ions: The loss due to stripping smaller than 5% per minute in the decay ring Possible to produce 1 1011 150Dy atoms/second (1+) with 50 microAmps proton beam with existing technology (TRIUMF) An annual rate of 1018 decays along one straight section seems as a realistic target value for a design study Beyond EURISOL DS: Who will do the design? Is 150Dy the best isotope? RAL 27 April 2006 The beta-beam task, EURISOL

Long half life – high intensities At a rate of 1018 neutrinos using the EURISOL beta-beam facility: RAL 27 April 2006 The beta-beam task, EURISOL

Gamma and decay-ring size, 6He Rigidity [Tm] Ring length T=5 T f=0.36 Dipole Field rho=300 m Length=6885m 100 938 4916 3.1 150 1404 6421 4.7 200 1867 7917 6.2 350 3277 12474 10.9 500 4678 17000 15.6 New SPS Civil engineering Magnet R&D RAL 27 April 2006 The beta-beam task, EURISOL

The beta-beam task, EURISOL 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. RAL 27 April 2006 The beta-beam task, EURISOL