Betabeams

1
Beta-beams

• M. Benedikt, A. Fabich, M. Lindroos
• CERN AB/ATB
• on behalf of the Beta-beam Study Group
• http//cern.ch/beta-beam
• FNAL Steering Group
• To develop a strategic roadmap for the
  accelerator-based HEP program

2
Outline

• Beta-beam concept
• EURISOL DS scenario
• Baseline layout
• Accelerator complex
• Limitation studies
• Decay ring
• Summary

3
Beta-beam principle

• Aim production of (anti-)neutrino beams from the
  beta decay of radio-active ions circulating in a
  storage ring
• Similar concept to the neutrino factory, but
  parent particle is a beta-active isotope instead
  of a muon.
• Accelerate parent ion to relativistic gmax
• Boosted neutrino energy spectrum En?2gQ
• Forward focusing of neutrinos ???1/g
• EURISOL scenario
• Ion choice 6He and 18Ne
• Based on existing technology and machines
• Study of a beta-beam implementation at CERN
• Once we have thoroughly studied the EURISOL
  scenario, we can easily extrapolate to other
  cases. EURISOL study could serve as a reference.

4
Acceleration scenario
M1.1 Final choice on baseline design M2.1 RCS
in/output parameters M3.1 PS/SPS in/output
parameters M4.1 Decay ring main parameters

• Cycle optimized for neutrino rate towards the
  detector for physics reach

• Documentation
• Parameters and intensity values
• Note Version 1 2005-01
• Note Version 2 2005-03
• Parameter database
• Note 2006-07

Bunch 20th 15th 10th 5th 1st
total
RCS optics
M2.2 RCS First order optics design

• Documentation
• Preliminary RCS design 2006-05
• RCS RF characteristics 2006-09

5
Limitations by decay losses

• Decay losses cause degradation of the vacuum due
  to desorption from the vacuum chamber

• Heat deposition and activation by beam losses
  limits the machine operation and lifetime.

P. Spiller et al., GSI
M3.2 Identification of limitation

• Documentation
• Beta-beam decay losses 2005-05
• Dynamic vacuum 2006-07

6
Space charge related issues

• Beam growth due to intra-beam scattering
• Simulation for 18Ne using MAD
• Growth time t should be larger than acceleration
  time taccel.

7
Decay ring
M4.2 Decay ring first order optics design

• Documentation
• First design for the optics of the decay ring of
  the beta-beams 2006-05
• Loss management 2007-0013

A. Chance et al., CEA Saclay
merging
p-collimation
injection
decay losses

• Particle turnover
• 1 MJ beam energy/cycle injected
• ? equivalent ion number to be removed
• 25 W/m average
• Requires a system of absorbers and collimators to
  remove
• the beam of parent and daughter ions.

8
Longitudinal penetration in coil
Superconducting Dipole Design
FLUKA simulation model
Power deposited in dipole
Coil
Abs
Coil
Coil
Abs
E. Wildner et al., CERN
No absorber
Carbon
Stainless Steel
9
Summary EURISOL DS

• No deviations from the initial planning.
• Beta-beam accelerator complex is a high technical
  challenge due to ion intensities without
  precedent.
• Activation and heat deposition
• Space charge
• So far ion acceleration for a EURISOL beta-beam
  scenario looks technically feasible.
• Short-fall of 18Ne production not yet resolved.
• Collaboration with EURISOL production task 3.
• Cross-sections for direct production currently
  measured at LLN.
• Alternative production scenarios might be
  investigated.

10
Ways forward Guideline to n-beam
scenarios based on radio-active ions

• Low-energy beta-beam relativistic g lt 20
• Physics case neutrino scattering
• Medium energy beta-beam g 100
• EURISOL DS
• Today the only detailed study of a beta-beam
  accelerator complex
• High energy beta-beam g gt350
• Take advantage of increased interaction
  cross-section of neutrinos
• Monochromatic neutrino-beam
• Take advantage of electron-capture process
• High-Q value beta-beam g 100
• Accelerator physicists together with neutrino
  physicists defined the accelerator case of
  g100/100 to be studied first (EURISOL DS).

11
A new approach for the production and high-Q

• Beam cooling with ionisation losses C. Rubbia,
  A Ferrari, Y. Kadi and V. Vlachoudis in NIM A 568
  (2006) 475487
• Many other applications in a number of different
  fields
• may also take profit of intense beams of
  radioactive ions.

7Li(d,p)8Li 6Li(3He,n)8B
7Li 6Li
See also Development of FFAG accelerators and
their applications for intense secondary particle
production, Y. Mori, NIM A562(2006)591
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(Higher) Gamma and decay-ring size, 6He
Civil engineering
Magnet RD
New SPS
13
Site constraints
Stretched Tevatron aimed at Soudan B? 3335
Tm R 1000 m (75 4.4T dipoles) LSS
3500 Total circumference approximately 2 x
Tevatron 320m elevation _at_ 58 mrad 26 of
decays in SS
14
Next step in Europe for neutrino oscillation
physics

• We have some questions to answer
• Considering safety, cost and feasibility can we
  agree on a set of baselines for the proposed
  future neutrino oscillation facilities?
• How do we compare the different facilities?
• Can we propose a road map for the future of this
  subject?
• Attempt to address some of these issues in a new
  European design study proposal for a future
  neutrino oscillation facility
• Euron DS

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Summary

• EURISOL DS beta-beam (g100) is Study I for
  beta-beams
• This first study had limited ambitions
• The physics reach for the EURISOL DS scenario is
  competitive for q13gt1O.
• Usefulness depends on the short/mid-term findings
  by other neutrino search facilities.
• If we want to improve the physics reach what are
  the ways forward
• Higher g ( gt 100)
• Higher intenisty
• High Q value isotopes
• Staging of the facility makes a lot of sense if
  it is possible to do experiments with
  anti-neutrinos first
• Easy to produce 6He and 8Li with small and
  compact production unit e.g. low energy but high
  power proton/deuterium driver
• A Study II for beta-beams in the US!
• The proposed Euron DS but it will only give us
  very limited resources for RD, mostly review
  work. It can run in parallel to a study in the US
  (link through IDS mechanism)
• FNAL would be an excellent site for a beta-beam
  considering e.g. ramp time of existing
  accelerators and space on the site for a large
  ring
• The European beta-beam team is willing to help
  giving a possible US beta-study a flying start
• Explore link to ANL at an early stage to get US
  RNB experts involved, will represent major time
  gain
• Links to other projects should be investigated
  e.g. new dipoles for upgrade of LHC injection
  region