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

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4. September 23rd, 2011IceCube Meeting Uppsala4 Four journal publications: Y. Abdou et al., arXiv: 1105.4339, subm. to NIMA technical paper R. Abbasi et al., APP 33(2010)277 speed of sound R. Abbasi et al., APP 34(2011)382att. length R. Abbasi et al.,arXiv:1103.1216, subm. to APPnoise&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 !

5. September 23rd, 2011IceCube Meeting Uppsala5 Sensor noise behavior stable over years: Compare 2009 2011

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7. September 23rd, 2011IceCube Meeting Uppsala7 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

8. September 23rd, 2011IceCube Meeting Uppsala8 Similar behavior found for later measurement with string D sensor

9. September 23rd, 2011IceCube Meeting Uppsala9 Aachen Acoustic Laboratory

10. September 23rd, 2011IceCube Meeting Uppsala10 Perform reciprocity calibration for AAL transmitters Do for SPATS3 - reciprocity cal. - hybrid cal. (use calibrated transmitter) Check result of early 2011

11. September 23rd, 2011IceCube Meeting Uppsala11 increase systematical error

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13. 13 Uppsala 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 Sascha Cramer

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15. September 23rd, 2011IceCube Meeting Uppsala15 waterSouth Pole icesalt  = c 2 k/C P 0.1531.122.87 f max (kHz)7.72042 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 still necessary

16. September 23rd, 2011IceCube Meeting Uppsala16 Venio Romam iterum crucifigi. Quo vadis, Domine? Quo vadis? From problems to success

17. September 23rd, 2011IceCube Meeting Uppsala17 J. Berdermann 1), M. Carson 2), R. Nahnhauer 1) 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 km 3 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

18. September 21st, 2011IceCube Meeting Uppsala18 The next radio detector at the Pole - ARA 37 clusters nearly without correlations per event No hybrid (acoustic) option foreseen and possible  holes too distant (1.3-2 km)  holes not deep enough 148 holes

19. September 23rd, 2011IceCube Meeting Uppsala19 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 on reasonable measurements Maryland 2009 Workshop

20. September 21st, 2011IceCube Meeting Uppsala20 Comparison with radio triggers II (model dep.) coinc. events/year (ESS-2008) LearnedAskaryanDedenko  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) LearnedAskaryanDedenko  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%

21. September 21st, 2011IceCube Meeting Uppsala21 Conclusions For 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 ok the deeper the better (200-1000m gives factor 2)  threshold dependence 10 mPa would be ok the lower the better, particularly for lower energies  grid constant dependence 500 m spacing would be ok 333m spacing better, particularly for lower energies In general: reasonable number of coincident events detectable only with large scale detector (~400 km 2 )

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25. September 23rd, 2011IceCube Meeting Uppsala25 Ultima hora latet