1. ARIANNA: A New Concept for Cosmogenic Neutrino Detection
Steven W. Barwick (UC Irvine)
A talk in honor of the life and work of Simon Swordy
November 19, 2010

2. ARIANNA: A New Concept for the Detection of GZK neutrinos
~1 km
Steven W. Barwick, UC-Irvine

3. Neutrino Telescopes: Agenda
10 years of progress with optical Cherenkov Detectors
Extremely Energetic Neutrinos - New Technologies
Radio Cherenkov: ARIANNA
Teraton -Petaton

4. PHOTONS: not deflected, but: reprocessed in sources, absorbed in IR (100 TeV), and CBR
PROTONS: deflection in magnetic fields, GZK cutoff
NEUTRINOS: not absorbed or deflected, hard to see

5. 1997: Unlimited Opportunity
E2 dN/dE (GeVcm-2s-1sr-1)
A. Silvestri, PhD Dissertation, 2008 WB
Log10(E[GeV])

6. 13 Years of Diffuse  Progress
2010
~100x improvement
E2 dN/dE (GeVcm-2s-1sr-1)
A. Silvestri, PhD Dissertation, 2008
Auger x3
ANITA
AMANDA-UHE WB
Log10(E[GeV])

7. Excluding AGN Model Predictions for Diffuse Flux
Excluded
Normalization to x-ray or MeV ’s overproduces neutrino flux

8. GZK neutrinos [ one of the the most secure predictions in the field ]
New Technologies

9. Cosmogenic (or GZK) Neutrinos
Predictions are secure:
p + cmb  ->  -> n + +
n -> lower energy protons
 -> 
However, -Flux Calculations depend on:
Elemental composition (p, Fe, mixed)
Cosmology (=0.7)
Injection Spectra, E- and Emax
Evolution of sources with redshift, (1+z)m
Star formation, QSO, GRB, little or no

10. GZK Model-Specific limits
all)
E dN/dE (cm-2s-1sr-1)
109 GeV
ANITA-08
Log10(E[GeV])

11. Why Big Detectors? So GZK  detection requires > 10 km3
GZK  Flux,  (E~1018 eV): /km2/yr
 Interaction Length, : km
Event Rate/km3/yr = [/] ~ 0.2
Efficiency, livetime, nice if more than one
So GZK  detection requires > 10 km3
(aperture > 60 km3sr)
Note: ARIANNA has ~ 2400 km3sr

12. ARIANNA Sensitivity
Greatly increases sensitivity to GZK  in E= eV
ARIANNA
+ ESS Flux:
40 events/yr
ARIANNA
Energy Res: dE/E~1,
Angular Res: ~1 deg

13. EHE Neutrinos Explore Higher Dimensions
~100sm
For GZK E
ARIANNA-GZK
CC: sm
(Anchordoqui, et al, hep-ph/ )

14. EHE Neutrinos Explore Lorentz Invariance Violation
ARIANNA (6 mo)
ARIANNA (5 yr)
No LIV
EF(E) (m-2sr-1s-1)
ARIANNA-GZK
Strong LIV
Log E (eV)
(Scully, Stecker, arXiv: v1)

15. Neutrino Cross-Section
A. Connolly, 2006
ARIANNA - 10 years
[ ] = 0.24
If Nev = 400
If  =0.5o
If =2GQRS
GQRS
2 parameter fit:
Normalization
cross-section

16. New Techniques to Observe Cosmogenic Neutrinos
Current
Under Development
Radio
RICE, ANITA
ARIANNA, ARA, IceRay, SALSA, etc
Air Shower
HiRes, Auger
TA, Auger N, OWL
Acoustic
SPATS, AMADEUS

17. Askaryan Radio Emission from SLAC beam in Ice
Gorham, Barwick, et al., astro-ph/
Absolute RF power and frequency dependence confirmed
Width of cherenkov cone and frequency dependence confirmed

18. ARIANNA 31 x 31 array [30 km x 30 km] 1 km 600 m
UCI, LBL, OSU, WashU, KU,UC-London, S.Korea
Barwick, astro-ph/

19. Satellite Image of Victoria Land and Ross Ice Shelf
Ross Island
Dry Valleys
wireless internet (2009)
~120 km
Minna Bluff
ARIANNA
30x30 km2
Ice Thickness ~600m
south

20. ARIANNA Advantages Straightforward logistics Excellent site properties
not far (~120 km) from main US science station
surface deployment (no drilling)
Excellent site properties
Protected from man-made noise
Remarkable attenuation length and reflectivity from bottom
Lightweight, robust technologies (so low $$)
Internet access 24/7
Array is reconfigurable to follow science

21. ARIANNA Characteristics
log(E) eV
Zenith Angle
Nearly uniform response
over the entire sky
Peak response at “sweet spot” of GZK spectrum

22. ARIANNA “Pointing”
Zenith Angle

23. Optimal Antenna Gain = 7 LPDA
higher gain restricts viewing of reflected events but accesses lower energy cascades
LPDA

24. Impact of firn ice on LPDA Antenna (not much, except at f<100MHz)
L. Gerhardt, et al, NIMA, 2010

25. Time-domain is rich in information
on-cone
off-cone
-10 10
Time(ns)
-10 10
Time(ns)
J. Alvarez-Muniz, A. Romero-Wolf, and E. Zas, arXiv: v1

26. Modification by antenna+amp
Interesting structure, well
suited to pattern trigger
Similar pulse structure for on-cone and off-cone
-60 60
Time(ns)

28. Camping at Moore’s Bay Site
David Saltzberg

29. ARIANNA Site Studies And Radio Quiet!
T. Barrella, et al., J. Glaciology, 2010
Value assumed prior to this work
Preliminary
Arbitrary amplitude scaling
Amazing fidelity of reflected pulse from sea-water bottom
-behaves as nearly flawless mirror
1-way attenuation length, averaged over depth and temperature
And Radio Quiet!

30. ARIANNA Prototype Station (deployed Dec. 2009)
L. Gerhardt, et al, NIMA, 2010
ARIANNA Prototype Station (deployed Dec. 2009)
Power Tower
Wireless
“lab”

31. Housekeeping Data Outside Temp windy Wind speed Power Supply Voltage
Jan 1, 2010
Feb 4, 2010

32. Trigger rates ~ 10-2 s-1
Randomly distributed in time
Trigger: 2 of 3 majority, 5*Vrms

33. Prelim. Event Analysis (Jan 5 -Feb 4, 2010)
No events in signal region

34. ARIANNA Visualization

35. Outlook
To probe the GZK neutrino fluxes and particle physics at highest energies, new techniques are being developed based on radio cherenkov , air shower and acoustic detection.
ARIANNA has the right combination of size and simplicity of deployment to keep costs down
Ice studies in Nov’ 06 astonishingly good
Recent protostation studies show low Anthropogenic noise over 1 month periods
7-station engineering array approved by NSF in April 2010

37. Air Shower vs Ice Shower (time profiles quite different!)
100MHz-1 GHz

38. Electronic Module Schematics
L. Gerhardt, et al, NIMA, 2010

39. Solar Panel Power
Electronic Module

40. GZK Cutoff (Experimentally Confirmed)
arXiv: v1