Summary of the Acoustic R&D Parallel Session R. Nahnhauer DESY September 23rd, 2011 IceCube Meeting Uppsala1 x AAL Quo vadis?

Summary of the Acoustic R&D Parallel Session

R. NahnhauerDESY

September 23rd, 2011 IceCube Meeting Uppsala 1

x

AAL

Quo vadis?

IceCube Meeting Uppsala 2September 23rd, 2011


x


Four journal publications:

Y. Abdou et al., arXiv: 1105.4339 , subm. to NIMA technical paperR. Abbasi et al., APP 33(2010)277 speed of soundR. Abbasi et al., APP 34(2011)382 att. lengthR. Abbasi et al.,arXiv:1103.1216, subm. to APP noise&transients

Five PhD Thesis

Several Bachelor, Master, Diploma Thesis

A lot of data could still be evaluated: inclined speed of sound noise sources shadowing effects frequency behaviour etc., ect.

Mission (nearly) accomplished !


Sensor noise behavior stable over years:Compare 20092011



Aim: learn more about detector efficiency vs. and learn more about noise sources (get hits in both channels of one sensor nearly only from acoustic signals, i.e. from reconstructed events - hint that measured noise level is caused by sensor electronics)

Distance: 10 cm


Similar behavior found for later measurement with string D sensor


AachenAcousticLaboratory


Perform reciprocity calibration for AAL transmitters Do for SPATS3- reciprocity cal.- hybrid cal. (use calibrated transmitter)

Check result of early 2011


increase systematical error


13Uppsala 21.09.2011 IceCube Collaboration meeting

A one layer PVDF acoustic sensor. Thermoacoustic effect in water

Oservations:Clean bipolar signal (thermoacoustics signal)Polarity inversion of the thermoacoustics signal at around 4 °C

Sascha Cramer Bachelor thesis

Sasc

ha C

ram

er



water South Pole ice salt

= c2k/CP 0.153 1.12 2.87

fmax (kHz) 7.7 20 42

signal strength ~ Gruneisen parameter

First reliable direct comparison of signal strength in water and ice !

Measurement confirms expectations for

Speed of sound Frequency Signal strength

Final calibration stillnecessary


Venio Romam iterum

crucifigi. Quo vadis, Domine?

Quo vadis?

From problems to success


J. Berdermann1), M. Carson2), R. Nahnhauer1) 1)DESY, 2)Gent University

How a hybrid radio-acoustic detector in ice could look like

Aim of the new simulation study

Check the general possibilities of a hybrid detector concept for a x*100 km3 cosmogenic neutrino detector Discuss some of the basic requirements for a necessary R&D program, as there are e.g.

- new (robotic) drilling and deployment technologies - new power and communication systems - new type of cable integrated sensors - new data collection, reduction and transfer concepts - etc. pp

It is NOT the aim of this study to work out a concept which tomorrow can be started to be build – the realistic timescale is at least of O(10years)

A 2-3 orders of magnitude larger detector than ever built can not just be a blow-up of an older one but needs new ideas and techniques

IceCube Meeting Uppsala 18September 21st, 2011

The next radio detector at the Pole - ARA

37 clusters nearly without correlations per eventNo hybrid (acoustic) optionforeseen and possible holes too distant (1.3-2 km) holes not deep enough

148 holes


Don’t give up the hybrid idea for UHE neutrino detection

still important because of :- Signal Identification

- Noise Reduction

- Detector Calibration

- Event Reconstruction

- Energy and Direction Resolution

Acoustic technology may do for low cost at least part of the job, as long as better alternatives are missing

Do now necessary simulations based onreasonable measurements

Maryland 2009 Workshop


Comparison with radio triggers II (model dep.)

coinc. events/year (ESS-2008)Learned Askaryan Dedenko

0.6 (6) 1.8 (18) 2.7 (27)

e 0.3 (3) 0.9 (9) 1.3 (13)

all 0.9 (9) 2.7 (27) 4.0 (40)

coinc. events/year (ESS-2008)Learned Askaryan Dedenko

2.1 (21) 5.0 (50) 6.3 (63)

e 1.0 (10) 2.4 (24) 3.0 (30)

all 3.1 (31) 7.4 (74) 9.3 (93)

10 mPa 1 mPa

6%11%

16% 35%

29%

18%


ConclusionsFor considered grid arrays in average about 10% of radio events have additional acoustic signal - ~80% of those give own acoustic trigger

depth dependence: 200-400 m would be okthe deeper the better (200-1000m gives factor 2)

threshold dependence10 mPa would be okthe lower the better, particularly for lower energies

grid constant dependence500 m spacing would be ok333m spacing better, particularly for lower energies

In general:

reasonable number of coincident events detectable only withlarge scale detector (~400 km2)





Ultima hora latet

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Summary of the Acoustic R&D Parallel Session R. Nahnhauer DESY September 23rd, 2011 IceCube Meeting Uppsala1 x AAL Quo vadis?