Projects of the next decade:

IceCube Meeting Berkeley 1March, 23 2005

Alternative Detection Methods for Highest Energy Neutrinos

Possibilities – Timescales - Competition

Rolf Nahnhauer, DESY

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Projects of the next decade:

All Radiation EeV Neutrino detection Arrays

observe > 10 events/year from GZK flux

Veff ≥ 50 km3

target material: water, ice, salt, rock?

profit from combination of different detections methods:

optical-acoustic-radio

in background reduction, cross calibration, detection sensitivity,…


The Water ARENA

+ Acoustic1000 hydrophone array for Mediterranean

3 hydrophones per cluster( sensor distance : 50 m )

300 m grid spacing

red line : incident neutrino (7.2*1019 eV)red cube : deposited energy of - interactionyellow points : hydrophonesgreen cubes : signal hits

From L. Thompson, unpublishedAnd U. Katz, ApPEC Workshop 2003


Water ARENA Sensor R&DErlangen :cheap selfmade hydrophones

sensitivity = 6x commercial S/N 10

pressure wave on fibre modulation of cavity size, leading to modulation of laser wavelength detectable by interferometer

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spectral response to a 65 kHz loud-speaker modulation

(Mach-Zender OPD = 150 m)

commercial

selfmade

From: P. Kollmannsberger, DPG 2004

From: M.Morganti, Roma 2005

Pisa, Firenze:fibre acoustic sensors


A Water ARENA Test Site

cable:10 OF; 6 conductors

A fully equipped facility to test and develop technologies for the Mediterranean km3

From G. Riccobene for this workshop

2004-2006

Shore laboratoryport of Catania

Underwater test site:25 km E offshore Catania

2000 m depth


NEMO “phase 1” frame

Successfully deployed on 23 Jan 2005

•4 hydrophones: • 2 (10 Hz - 40 kHz) ; 2 (1 kHz - 40 kHz)•Digitization (24 bits 96 kHz) and electro-optical translation •Continuous monitoring from shore

First tests: The NEMO - ODE (Ocean noise Detection Experiment)

From G. Riccobene for this workshop

Sperm whales clicks


The Water ARENAPreparation at Antares site in 2005

Spring deploy string-0, dummy+hydrophonescheck sensitivity, measure noise

Summerrecover string-0Autumn deploy string-1, string-2

each has five levels upper level 5x2 hydrophones

4 lower levels 5x3 PMT’s

Two strong groups: Erlangen , SheffieldMoney: ~2x500k EuroPersonpower (G): 10 students (PhD+diploma)

9 talks at German DPG 2005(1 talk from IC++)

Personpower(UK) ???


If LOPES R&D successful add radio detectors to AUGER

4 km 1EeV air shower

radio beam

2 km

50 km

1mV/m/Mhz

1

The Air ARENA

AUGER + Radio

vertical 1017 eV air shower

center+100m+250m

data:Allan and Prah

A. Horneffer et al., SPIE 2004


Iran, 7km diameter

Canada 8x5 km2

Many Gulf coast salt domes3-4 km diameters, 5-10 km depths typical

The Salt ARENA Imany big salt domes around the world

From M. Chiba, NANP-Dubna 2003

Typical salt dome: RF loss similar to ice at -40° C 2.5 times more dense build radio detector array


Halite (rock salt)• La(<1GHz) > 500 m w.e.• Depth to >10km• Diameter: 3-8 km• Veff ~ 100-200 km3 w.e.• No known background• >2p steradians possible

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Meeting at SLAC Feb/05 :SalSA Collaboration bornU-Hawaii,UCLA, SLAC, …

Basic array geometry simulatedP. Gorham talk at SLAC meeting

2.5 km3 array with 225 m spacing122=144 strings, 123=1728 antenna nodes12 antennas per node, dual polarization ~300 km3 sr at 1 EeVthreshold 1017 eV, few 100s antennas hit at 1 EeV, >1000 hits at 10 EeV

Rate: claim at least 10 events per year from rock-bottom minimal GZK predictions

Phase 1: look for right locationdeploy test strings in a few holes study attenuation, noise etc in-situ

The Salt ARENA I


The Salt ARENA IAdd acoustic detector array to SalSA?

Theoretical expectations :

Water

Ice Salt

ρ [g/cm3]

1 .9 2.1

Vs [m/s] 1450 3800 4500

P/Pwater

1 10 25

f/fwater 1 ~3 ~6

eff. abs ~km 7 ? km

noise large small ?

small ?From B.Price at SLAC meeting 02/05

Need measurements :learn from geophysicists

f = 1 – 100 kHz, fres = 150 kHz

Signal attenuationλatt = 1/α

S = Ae-αr/rn

n = 2 usedλatt ≈ 170 m !

Signal location< 1 m

T. Spies, J. Eisenblätter, J.Manthei,Z. f. angewandte Geologie, H2, 2002, 30and references therein

1 crack seen by 12 detectorspressure waves + shear waves


The Salt ARENA II

http://www.lofar.org

interferometer in frequency range of 10 - 200 MHzarray of 100 stations of 100 dipole antennasbaselines of 10 m to 400 km

All-Sky monitor: transient events

LOFAR

salt pillars

Zechstein salt

Detect UHE ’s using rock salt in Northern Europe (Groningen)Monitor UHE CR’s with LOFARDevelop:

radar techniques for salt domestechniques to install antennas in salt domes

LOFAR + ZESANAZuidwending

Onstwedde

Zuidwending

7,5 km

From A. M. van den Berg, SLAC meeting 02/05A. M. van den Berg, SLAC meeting 02/05


The Ice ARENA

IceCube Collaboration:

Study a hybrid optical-radio-acoustic array

Idea behind: try to cross calibrate the detector,if discovery is made with one technique, confirmation with different technique necessary

IC++ :o radio +acoustic optical (IceCube) o+r+a (IceCube+)

example:0.5 km spacing1.5 km strings91 stringsVeff = 58 km3

λabs min Nch GZK (H+S) events/year

1 km 4 min 0.5

1km 4 max 1.5

6 km 4 min 18

6 km 4 max 54

acoustic array alone:

acoustic noise :

From J. Vandenbroucke,IceCube meeting Uppsala 10/04


The Ice ARENA Radio antennas for ice available and tested (RICE)Acoustic glaciophones under development :

iron ball

glass ball

Calibration (until now only in water)reference hydrophone: Sensortech SQ03: -163.3±0.3 dB re 1V/μPa

Improvement

(S/N)ib = 50 (S/N)gb = 15

From S. Böser et al., to be published

Testrun at proton beam:

Etot = 5.6 PeV – 1.7 EeVE min (1m) 10 PeV

P min: ~10 mPa


The Ice ARENA Ice properties for propagation of light measured (AMANDA)Ice properties for propagation of radio signals measured (RICE)Ice properties for propagation of sound waves still to be measured

urgent requirement: study ambient noise measure absorption length

test foreseen for season 05/06

x Proposal:

use 3 holesdiameter: ≥ 6” depth: 400 m7 sensors per holelarge variation of ice properties at the surface non-equal spacing7 transmitters per holeno possibility for transmitter allingment azimuthal symmetry


Timescale and Competition

Project R&D time R&D funding Realization Problems

KM3Net + acoustic 2004-2008 ~1 Mio E > 2012 deployment, cost

AUGER + Radio 2004-2008 ??? > 2008 AUGER Nord

SalSA + (acoustic) 2005-2008 3-5 Mio $ > 2008 location, acoustic, cost

ZESANA + LOFAR 2005-2008 ??? > 2010 cost

IC++ opt./rad./acou.

2003-2007 0.1 Mio E > 2010 location,acoustic

A hybrid extension could make IceCube the pre-eminent neutrino telescope at all cosmic energies

But other projects near to take over


International ARENA Workshop

May, 17 – 19 2005

DESY, Zeuthen, GERMANY

http://www-zeuthen.desy.de/arena


Summary + ConclusionsFor the observation of the tiny neutrino fluxes above 1018 eV

Optical detection techniques seem to reach their limits

Radio detectors start to become sensitive

Acoustic detectors have a big revival but still need R&D

Further progress would profit from

Combination of different detection techniquesin one project

Dedicated experiments at large scales

Network of worldwide cooperation

Documents

Projects of the next decade: