1. High Current Cyclotrons for Future Neutrino Experiments
L. Calabretta, INFN-LNS,
for the DAEdALUS collaboration
Workshop on Neutrino Telescopes, Venice March 2013

2. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
DAEδALUS: A Path to Measuring δCP Using Decay-at-Rest Neutrino Sources, by J. Conrad & M. Shaevitz
Primary physics goal: searching for
Decay At rest Experiment for δcp studies At the Laboratory for Underground Science
CP-violation in the neutrino sector
Short baseline nμ ne experiment with no matter effect
novel design which provides high-statistics and low backgrounds
Workshop on Neutrino Telescopes, Venice March 2013

3. Workshop on Neutrino Telescopes, Venice 11-15 March 2013

4. Workshop on Neutrino Telescopes, Venice 11-15 March 2013

5. is absent in the flux: look for its appearance!
Shape driven by nature!
Only the normalization varies from beam to beam
is absent in the flux: look for its appearance!
Workshop on Neutrino Telescopes, Venice March 2013

6. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Single Ultra large Detector
With Free Protons as IBD (ne + p  e+ + n) Targets
Three Identical Beams
Workshop on Neutrino Telescopes, Venice March 2013

7. The duty factor is flexible, but beam-off is needed.
2 ms
2 ms
8 ms
1.5 km Accelerators
8 km Accelerators
20 km Accelerators
800 5 MW
800 2 MW
800 1 MW
To identify the source that produced the detected neutrino, the accelerators are driven with a 20% duty cycle: <2 MW> peak power 10 MW or higher
The duty factor is flexible, but beam-off is needed.
Workshop on Neutrino Telescopes, Venice March 2013

8. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Accelerator requirements in perspective
AVERAGE power
PEAK power
ESS
Workshop on Neutrino Telescopes, Venice March 2013

9. Cyclotrons: Viable technology?
PSI is current world power leader in this energy range
~ 1.4 MW average, 590 MeV protons
Extrapolation to higher power?
Problems:
Capture of more ions… space-charge at injection
Clean extraction… max loss 200 W (~10-4)
VIS source
Superconducting Ring Cyclotron
Normal conducting Cyclotron
Workshop on Neutrino Telescopes, Venice March 2013

10. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Proposed Solution: H2+ ions
Two protons for every ion (1 emA = 2 pmA)
Perveance of 5 emA H2+ at 35 keV/amu same as 2 emA of 30 keV protons
Axial injection of 2 emA protons at 30 keV is well within state of the art
Extraction with stripping foil
Clean turn separation is not needed, only high-acceptance extraction channel
Workshop on Neutrino Telescopes, Venice March 2013

11. The base cyclotron module for DAEDALUS is designed to deliver proton beam MeV duty cycle 20%, average power <1.6 MW>
Superconducting Coils, Losses due to residual gas,
Electromagnetic stripping
Peak current 5mA of H2+
< 1 mA> H2+ 60 MeV/n <120 kW>/600 kW peak
< 1 mA> H MeV/n %<1.6 MW> MW peak
Stripping extraction
Space Charge effects, Electrostatic Deflectors
Workshop on Neutrino Telescopes, Venice March 2013

12. H2+ beam Stripper foil emerging protons electrons catcher
Stripper foil: 5 MW 800 MeV Xing a stripper foil 1 mg/cm2 thick release  45 W due to nuclear interaction!
The electrons removed by the strippers have a full power of 5 MW*Me/MH2=5/(2*1826)=1370 W !
Electrons are the main source of stripper damage
But, electrons can be stopped before strike the stripper
Stripper foil
emerging
protons
H2+ beam
electrons
catcher
If B=0.4 T Re=4.5 mm
Stripper Thickness can be also thinner, because:
H- =(p+e+e)  p, e, e is a two steps process (p+e+e) H + e  p, e, e
H2+ =(p+p+e)p, p, e is a single step process, lower probability for
H2+H + p
The neutral H can be removed by an additional stripper foil, 10 cm later
Workshop on Neutrino Telescopes, Venice March 2013

13. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
DAEdALUS Superconducting Ring Cyclotron
Space charge effects have negligible effects during acceleration in the ring cyclotron
Vertical beam size along the acceleration in the radial range from 4 to m, snapshot at 0° azimuth. The left figure has no charge space effects, 0 mA. The right figure is evaluated with a 5 mA beam H2+ current
Simulation made by J. Yang and A. Adelman (PSI), using OPAL code
Workshop on Neutrino Telescopes, Venice March 2013

14. The radial size of the beam depend mainly by the energy gain per turn
DE/E% phase (deg)
Z (mm) R (mm)
Histogram of 5 mA H2+ beam at the stripper foil position, simulation include space charge effects (OPAL code)
Workshop on Neutrino Telescopes, Venice March 2013

15. Effect due crossing Walkinshaw resonance
Workshop on Neutrino Telescopes, Venice March 2013

16. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Preliminary study of cryostat made by J. Minervini MIT-PSFC arXiv.org > physics > arXiv:
Workshop on Neutrino Telescopes, Venice March 2013

17. Electrostatic deflectors
Injector Cyclotron
60 MeV/amu, peak current 5 mA H2+
Normal conducting coils ~ 4.4 meter coil diameter
• Axial injection
(spiral inflector)
• Electrostatic
extraction
channel
Extraction trajectory
Coil
Electrostatic deflectors
arXiv:
Workshop on Neutrino Telescopes, Venice March 2013

18. Vertical beam size vs. turns number for different beam current
1 MeV/n
61.7 MeV/n
Vertical beam size vs. turns number for different beam current
Workshop on Neutrino Telescopes, Venice March 2013

19. Workshop on Neutrino Telescopes, Venice 11-15 March 2013

20. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Deflector septum 0.5 mm thick
Extraction efficiency 99.98%, if beam power is 600 kW on the septum 120 W!
Workshop on Neutrino Telescopes, Venice March 2013

21. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Development Strategy
With highly-complex projects:
Develop phased approach
Design phases such that good physics can be done with each
In our case… Injector cyclotron can in itself be a “barn-burning” neutrino source
The IsoDAR Project
10 mA (CW) proton at 60 MeV= 600 kW!
Workshop on Neutrino Telescopes, Venice March 2013

22. PhaseII: IsoDAR (Isotope Decay At Rest)
Proton beam into neutron-producing target
Secondary neutrons into ~50 kg pure 7Li blanket
8Li decay produces ne, high beta endpoint energy
Good for discriminating background
As with DAEdALUS, use IBD in liquid scintillator
Good spatial, energy resolution _
60 MeV, 600 kW
ISODAR
on PRL highlight
GOAL: STERILE NEUTRINO SEARCH
Workshop on Neutrino Telescopes, Venice March 2013

23. Oscillations can be seen within detector!
Workshop on Neutrino Telescopes, Venice March 2013

24. SNO+ also encouraging IsoDAR
Workshop on Neutrino Telescopes, Venice March 2013

25. Workshop on Neutrino Telescopes, Venice 11-15 March 2013

26. Injection test at “Best Cyclotron Inc.” site in Vancouver
Phase I
Is in progress
Injection test at “Best Cyclotron Inc.” site in Vancouver
Ion source
Injector Cyclotron
Superconducting Ring Cyclotron
Target/Dump
DAEdALUS Near site
Mini Cyclotron
Gate Valve
slits, emittance meter, buncher
VIS on
HV Platform
Solenoid
Quads
Solenoid
Ion source VIS and its beam line leaved Catania harbour on February 15, now are traveling ocean
Vacuum Pumps
Workshop on Neutrino Telescopes, Venice March 2013

27. beam injection in the median plane
liner
housing
liner
dee #2
spiral inflector
dee #1
liner
liner
TS - magnet
beam injection in the median plane
Workshop on Neutrino Telescopes, Venice March 2013

28. Workshop on Neutrino Telescopes, Venice 11-15 March 2013

29. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Phase III:
SRC & Target/Dump,
Ion source
Injector Cyclotron
Superconducting Ring Cyclotron
Target/Dump
DAEdALUS Near site
Workshop on Neutrino Telescopes, Venice March 2013

30. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Phase IV:
This is a tentative solution for the far site. Two injector cyclotron injecting in one SRC.
Two beams are extracted at the same time by two different stripper foils to mitigate the power dissipation on the beam dump.
Workshop on Neutrino Telescopes, Venice March 2013

31. Workshop on Neutrino Telescopes, Venice 11-15 March 2013
Summary
H2+ ions can be a key to high-power cyclotrons for many applications
Compactness and relative lower cost of cyclotrons could open doors to several important neutrino experiments
Exciting times ahead!
Workshop on Neutrino Telescopes, Venice March 2013

32. ...And thats all folks! Thanks for your attention!
Workshop on Neutrino Telescopes, Venice March 2013