ARIANNA: A New Concept for Cosmogenic Neutrino Detection Steven W. Barwick (UC Irvine) A talk in...
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Transcript of ARIANNA: A New Concept for Cosmogenic Neutrino Detection Steven W. Barwick (UC Irvine) A talk in...
ARIANNA: A New Concept for Cosmogenic Neutrino DetectionSteven W. Barwick (UC Irvine)
A talk in honor of the life and work of Simon Swordy
November 19, 2010
Neutrino Telescopes: Agenda
• 10 years of progress with optical Cherenkov Detectors
• Extremely Energetic Neutrinos - New TechnologiesRadio Cherenkov: ARIANNA
Teraton -Petaton
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
1997: Unlimited Opportunity
WB A. S
ilve
stri
, PhD
Dis
sert
atio
n, 2
008
Log10(E[GeV])
E2 d
N/ d
E (
Ge V
c m-2s-1
s r-1)
13 Years of Diffuse Progress
WB
~100x improvement
A. S
ilve
stri
, PhD
Dis
sert
atio
n, 2
008
Log10(E[GeV])
E2 d
N/ d
E (
Ge V
c m-2s-1
s r-1)
2010
AMANDA-UHE
ANITAAuger x3
Excluding AGN Model Predictions for Diffuse Flux
Excl
ud
ed
Normalization to x-ray or 1-1000 MeV ’s overproduces neutrino flux
Cosmogenic (or GZK) NeutrinosCosmogenic (or GZK) Neutrinos Predictions are secure:
p + cmb-> -> n + +
n -> lower energy protons
-> However, -Flux Calculations depend on:
1. Elemental composition (p, Fe, mixed)2. Cosmology (=0.7)3. Injection Spectra, E- and Emax
4. Evolution of sources with redshift, (1+z)m
Star formation, QSO, GRB, little or no
Why Big Detectors?
• GZK Flux, (E~1018 eV): 100 /km2/yr
Interaction Length, : 500 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
ARIANNA Sensitivity
Greatly increases sensitivity to GZK in E=1018-1019 eV
ARIANNA
ARIANNA+ ESS Flux:40 events/yr
Energy Res: dE/E~1, Angular Res: ~1 deg
AR
IAN
NA
-GZ
K
~100sm
For GZK E
CCsm
(Anchordoqui, et al, hep-ph/0307228)
EHE Neutrinos Explore Higher EHE Neutrinos Explore Higher DimensionsDimensions
AR
IAN
NA
-GZ
K
(Scully, Stecker, arXiv:1008.4034v1)
EHE Neutrinos Explore Lorentz EHE Neutrinos Explore Lorentz Invariance ViolationInvariance Violation
No LIV
Strong LIV
Log E (eV)
ARIANNA (6 mo)
ARIANNA (5 yr)
E
(E)
(m-2sr
-1s-1
)
Neutrino Cross-Section
] = 0.24 If Nev = 400If =0.5o
If =
2 parameter fit:Normalizationcross-section
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
ARIANNA - 10 years
GQRS
A. Connolly, 2006
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
Askaryan Radio Emission from SLAC beam in Ice
Absolute RF power and frequency dependence confirmed
Width of cherenkov cone and frequency dependence confirmed
Gorham, Barwick, et al., astro-ph/0611008
ARIANNAUCI, LBL, OSU, WashU, KU,UC-London, S.Korea
31 x 31 array [30 km x 30 km]
600
m
Barwick, astro-ph/0610631
1 km
Satellite Image of Victoria Land and Ross Ice Shelf
Ross Island
Dry Valleys
ARIANNA
south
Minna Bluff
~120
km
30x30 km2
Ice Thickness ~600m
wir
eles
s in
tern
et (
2009
)
ARIANNA Advantages
• Straightforward logistics– 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
ARIANNA Characteristics
Peak response at “sweet spot” of GZK spectrum
Nearly uniform response
over the entire sky
log(E) eV Zenith Angle
Optimal Antenna Gain = 7
LPDA
higher gain restricts viewing of reflected events but accesses lower energy cascades
Time-domain is rich in information
on-cone
J. Alvarez-Muniz, A. Romero-Wolf, and E. Zas, arXiv:1002.3873v1
off-cone
-10 10Time(ns) -10 10Time(ns)
Modification by antenna+amp
Interesting structure, wellsuited to pattern trigger
Time(ns)
Similar pulse structure for on-cone and off-cone
60-60
Amazing fidelity of reflected pulse from sea-water bottom-behaves as nearly flawless mirror
ARIANNA Site Studies
Value assumed prior to this work
Preliminary
1-way attenuation length, averaged over depth and temperature
Arbitrary amplitude scaling
And Radio Quiet!
T. Barrella, et al., J. Glaciology, 2010
ARIANNA Prototype Station(deployed Dec. 2009)
QuickTime™ and aTIFF (Uncompressed) decompressor
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WirelessPower Tower“lab”
L. Gerhardt, et al, NIMA, 2010
QuickTime™ and aTIFF (LZW) decompressor
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Trigger rates ~ 10-2 s-1
Randomly distributed in time
Trigger: 2 of 3 majority, 5*Vrms
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
Electronic Module Schematics
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L. G
e rha
rdt,
et a
l, N
IMA
, 201
0
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Solar Panel Power
Electronic Module