Development of Telescopes for Extremely Energetic Neutrinos

~1

km

Steven W. Barwick, UC-Irvine

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

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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

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Log10(E[GeV])

E2 d

N/ d

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c m-2s-1

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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

GZK neutrinios[ one of the the most secure predictions in

the field ]

New Technologies

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

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GZK Model-Specific limits

all)

Log10(E[GeV])

E d

N/d

E (

cm-2s-1

sr-1)

AN

ITA-08109 GeV

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

Neutrino Cross-Section

] = 0.24 If Nev = 400If =0.5o

If =

2 parameter fit:Normalizationcross-section

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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

Impact of firn ice on LPDA Antenna

(not much, except at f<100MHz)

L. Gerhardt, et al, NIMA, 2010

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

Camping at Moore’s Bay Site

David Saltzberg

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, submitted

ARIANNA Prototype Station(deployed Dec. 2009)

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WirelessPower Tower“lab”

L. Gerhardt, et al, NIMA, 2010

Housekeeping Data

OutsideTemp

Wind speed

PowerSupply Voltage

Jan 1, 2010 Feb 4, 2010

windy

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Trigger rates ~ 10-2 s-1

Randomly distributed in time

Trigger: 2 of 3 majority, 5*Vrms

Prelim. Event Analysis(Jan 5 -Feb 4, 2010)

No events in signal region

ARIANNA Visualization

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

Air Shower vs Ice Shower(time profiles quite different!)

100MHz-1 GHz

Electronic Module Schematics

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L. G

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IMA

, 201

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Solar Panel Power

Electronic Module