1. Elena Wildner, CERN For the Beta Beam Collaboration
Beta Beams
Elena Wildner, CERN
For the Beta Beam Collaboration
HEP 2011, Beta Beams, Elena Wildner 1

2. The Beta Beam Facility Collaborations
P. Zuchelli:” A novel concept for a neutrino factory: the beta-beam”, Phys. Let. B, 532 (2002)
FP6 “Research Infrastructure Action - Structuring the European Research Area” EURISOL DS Project Contract no RIDS)
Ended 2008
FP7 “Design Studies” (Research Infrastructures) EUROnu (Grant agreement no.: )
Ongoing work from 2008
Lasts till fall 2012
Focus on a feasible and realistic facility with good physics reach 2
HEP 2011, Beta Beams, Elena Wildner

3. Neutrino Beams from Beta Beams
Produce suitable beta (+/-) active isotopes
Available reaction energy of a specific isotope: Q
Accelerate beta active isotopes
The ions will get a maximum gamma boost gmax (En  2gmaxQ)
Store them and let them decay in a race track storage ring
gmax
depends on the available accelerators
depends on the Z/A of the ion
is chosen for the physics reach wanted
Merit factor: g/Q
Lower flux with distance
Higher x-sections with energy
Higher flux with g 3
HEP 2011, Beta Beams, Elena Wildner

4. HEP 2011, Beta Beams, Elena Wildner
High-Q and Low-Q pairs
Isotope
6He
18Ne
A/Z 3
1.8
decay
b -
b +
t1/2 [s]
0.81
1.67
Q [MeV]
3.51
3.0
8Li and 8B
6He and 18Ne
NuBase
t1/2 at rest (ground state)
1 – 60 s
1ms – 1s
Isotope
8Li 8B
A/Z
2.7
1.6
decay
b -
b +
t1/2 [s]
0.83
0.77
Q [MeV]
12.96
13.92
Higher Q-value gives higher n-energy, better x-sections but needs longer baseline 4
HEP 2011, Beta Beams, Elena Wildner

5. HEP 2011, Beta Beams, Elena Wildner
Beta beams at CERN
Use of CERN machines and infrastructures, existing technology
Beta Beam are unique to CERN
Bunching and first acceleration: ECR, linac
Rapid cycling synchrotron
Use of existing machines: PS and SPS
Relativistic gamma=100 for both ions
SPS allows maximum of 150 (6He) or 250 (18Ne)
Gamma choice optimized for physics reach
Opportunity to share detectors with astrophysics etc. ???
Frejus, Gran Sasso, Canfranc, CNGS-Umbria, …
Minimum n-rates after Decay Ring for physics reach
2.9*1018 anti-neutrinos from 6He
neutrinos from 18Ne
beta beams (CERN) 5
HEP 2011, Beta Beams, Elena Wildner

6. HEP 2011, Beta Beams, Elena Wildner
CERN Beta Beams, Synoptic
RCS
Baseline
Dotted lines: alternative layouts
SPL
Linac4
Linac
ISOL target
Molten Salt Loop
Collection PR
6He
18Ne
n-Beam
8B/8Li
6He/18Ne
ECR
RFQ
Linac 100 MeV DR PS
What is changing is mainly the production
SPS
PS and SPS existing
RCS
Decay Ring: Br ~ 500 Tm, B = ~6 T, C = ~6900 m, Lss= ~2500 m, g = 100, all ions 6
HEP 2011, Beta Beams, Elena Wildner

7. HEP 2011, Beta Beams, Elena Wildner
CERN Beta Beams, Synoptic
Dotted lines: alternative layouts
RCS
SPL
Linac4
ISOL target
Molten Salt Loop
n-Beam Fréjus
6He
18Ne
ECR
RFQ
6He/18Ne
Linac 100 MeV DR PS
What is changing is mainly the production
SPS
PS and SPS existing
RCS
Br ~ 500 Tm, B = ~6 T, C = ~6900 m, Lss= ~2500 m, g = 100, all ions 7
HEP 2011, Beta Beams, Elena Wildner

8. HEP 2011, Beta Beams, Elena Wildner
EUROnu physics
Gamma 100
Gamma 100
Gamma 350
Gamma 350
Gamma 350
M. Mezetto
Gamma 100 8
HEP 2011, Beta Beams, Elena Wildner

9. HEP 2011, Beta Beams, Elena Wildner
CPV
Flux
Systematics SF
The systematic error estimation is important (detectors and beam)
Beta beam neutrino flux can be calculated with current monitors in the accelerator.
Extend plots (calculations) to higher theta13
Reduction of Suppression needed for atmospheric background !!!
Flux 9
HEP 2011, Beta Beams, Elena Wildner

10. CPV for the Fréjus option (6He&18Ne)
Courtesy E. Fernandez, P. Coloma, C. Hansen
SF for atmospheric bg suppression:
serious constraint for bBeams
Larger sin22q13
constraint is relaxed
larger bunches permitted
higher neutrino fluxes
Calculations should be extended
range beyond Chooz limit ?
SF 2% seems sufficient for larger sin22q13 (0.6% used up till now) 10
HEP 2011, Beta Beams, Elena Wildner

11. CPV - nFlux: Fréjus &Canfranc
Courtesy E. Fernandez, P. Coloma, C. Hansen
Nominal flux
Dashed SuperBeam to Fréjus
2*Nominal flux
5*Nominal flux
Fréjus, SF 1%
Canfranc, SF 1%
Fréjus:18Ne ( n/year) & 6He ( n/year), g=100
Canfranc:18Ne ( n/year, g=250) & 8He ( n/year, g=100)
Other ion combinations may be efficient (A. Donini)
Negative delta, matter effects give degeneracies with the mass hierarchy.
Larger flux: no degeneracies, sensitivity for negative delta would increase, measurement of the mass hierarchy would be possible
Systematics from big fiducial volume not good
Liquid Argon for Canfranc? 11
HEP 2011, Beta Beams, Elena Wildner

12. HEP 2011, Beta Beams, Elena Wildner
Mass Hierarchy
Canfranc, Beta Beam setting:
and
Flux:
Nominal
2* Nominal
5* Nominal 12
HEP 2011, Beta Beams, Elena Wildner

13. HEP 2011, Beta Beams, Elena Wildner
Beta Beam Challenges
Isotope production ok now !
n emmitters “easy” to produce, measured rates are sufficient
n are more difficult: we can make them “on paper”
Exp. for Ne18 production verification are ongoing
Atmospheric background suppression
We loose particles from necessary collimation
We get short intense bunches in the Decay Ring, may get unstable
We can relax the suppression with recent results from T2K!
High intensities in the existing machines
Beam instabilities
Radiation
Follow carefully the LHC injector upgrades
The present machine cycles
Optimization possible 13
HEP 2011, Beta Beams, Elena Wildner

14. Isotope production rates
Aim: for low-Q
Targets below MWatt is a considerable advantage!
More is possible
Planned experiments
NB :8Li can be produced in rates comparable to 6He using similar technology
T. Stora, P Valko, E. Benedetto, E. Wildner…
HEP 2011, Beta Beams, Elena Wildner

15. HEP 2011, Beta Beams, Elena Wildner
Status, technologies
SF in Decay Ring (CERN, Cockroft)
RF hardware seems feasible
60 GHz Ion Source (LPSC, CNRS, Grenoble)
Tests of magnetic field for plasma containment ok
Tests of assembly with 28 GHz (emmittances and efficiencies)
60 GHz gyrotron: awaiting reception 2012
Collection of high-Q ions from production ring (UCL, Louvain)
Collection ok
Efficiencies now measured
Measurements of x-sections 8B and 8Li (INFN, Legnaro)
Analysis of results available in September
Decay Ring Redesigned (CEA)
Collective effects less important
Collimation in Decay Ring (CERN)
Needs good solution 15
HEP 2011, Beta Beams, Elena Wildner

16. HEP 2011, Beta Beams, Elena Wildner
Implementation and Costing
How to chose a facilty?
Performance/Cost
Part of EUROnu mandate
Synergy bB/SB
Safety has to be included
HEP 2011, Beta Beams, Elena Wildner

17. HEP 2011, Beta Beams, Elena Wildner
Conclusion
T2K: Optimization for excellent physics reach is ongoing
We can now reduce the SF for bg suppression (if T2K)
Flux will be considerably increased
Optimization of L/E
SPS can give gamma up to 250 for 18Ne, may be interesting now
Systematic errors need complete evaluation
Detector, WC but also Liquid Argon (EUROnu WP5)
Beam (alignment and current monitoring in accelerator)
To be included in the comparison analysis (all facilities)
Technical work in very good progress
isotope production confirmed for 6He, 18Ne experiment ongoing
Ion source being tested
Cross section measurements for high-Q isotopes ok
All results have to be iterated
Work on physics and accelerators in collaboration to be continued 17
HEP 2011, Beta Beams, Elena Wildner

18. Thank you for your attention HEP 2011, Beta Beams, Elena Wildner 18 18
HEP 2011, Beta Beams, Elena Wildner

19. HEP 2011, Beta Beams, Elena Wildner
Support slides 19 19
HEP 2011, Beta Beams, Elena Wildner

20. The Production Ring (8B and 8Li)
Production of 8B and 8Li
C. Rubbia, EUROnu proposal
Gas Jet target proposed in FP7:
too high density would be needed
vacuum problems
Direct Production (D. Neuffer) with liquid film targets
Collaboration ANL (Benedetto/Nolen)
Aachen Univ., GSI, CERN
High-Q 8B and 8Li will not be considered for the time being
We will not explore the low-Q gamma 350 option 20
HEP 2011, Beta Beams, Elena Wildner

21. HEP 2011, Beta Beams, Elena Wildner
Managing intensities: “Ion Cocktails”
Collective effects important
Less collective effects
Summary by A. Donini
HEP 2011, Beta Beams, Elena Wildner

22. HEP 2011, Beta Beams, Elena Wildner
Collective Effects limits, Decay Ring
Only Transverse Mode Coupling Instabilities
Recent Encouraging results, redesigned decay ring !
Phase slip factor changed
C. Hansen, CERN & A. Chance, CEA 22
HEP 2011, Beta Beams, Elena Wildner

23. Atm. Background suppression
1014 ions, ~0.5% duty (supression) factor can now be reduced
Gives possibilities to give more neutrino flux
20 bunches, 5.2 ns long, distance 23*4 nanosseconds
filling 1/11 of the Decay Ring, repeated every 23 microseconds
Work on HW feasibility by
Cockroft institute/Lancaster Univ.
G. Burt 23 23
HEP 2011, Beta Beams, Elena Wildner

24. HEP 2011, Beta Beams, Elena Wildner
Collection device
Measurements/Analysis ongoing for the collected 8Li
Direct kinematics is possible, efficiencies to be evaluated
Setup and measurements for 8B production and collection ongoing
CRC, Louvain la Neuve
HEP 2011, Beta Beams, Elena Wildner

25. X-sections, Energies and Angles, Li and B
2011
Measurements are finished !
INFN, Legnaro 25
HEP 2011, Beta Beams, Elena Wildner
E.Vardaci

26. HEP 2011, Beta Beams, Elena Wildner
60 GHz Source status
28 GHz
waveguide
High voltage
ring
Plasma chamber
Plasma
electrode
Extraction
insulator
Puller
Conceptual design of the internal parts of the ECRIS prototype
Delivery of the GANIL 28 GHz gyrotron to LPSC
LPSC-LNCMI discussions for experiments
Ion beam at 28 GHz with SEISM prototype (fall 2011)
Magnetic field measurements, A (60 GHz)
Design of the High intensity beam line
Follow-up the 60 GHz gyrotron building
400 A Power supply
and magnet
LPSC Euronu contract status
Hiring a one year post-doc
T. Lamy 26
HEP 2011, Beta Beams, Elena Wildner