IceCube Spring Meeting 2007 Parallel Session ++ Future Directions - Acoustic

1. IceCube Spring Meeting 2007 Parallel Session ++Future Directions - Acoustic Rolf Nahnhauer DESY Rolf Nahnhauer IceCube Spring Meeting

2. SPATS Freija Descamps Justin Vandenbroucke Deployment successful Detector operates well Data taking ongoing First preliminary results available As usual for start of an experiment in an unexplored region: more questions than answers Rolf Nahnhauer IceCube Spring Meeting

3. Unexpected Mysteries 1) Holes freeze (partly?) from below 2) Width of gaussian noise is ~twice as large as in laboratory- or lake tests and increasing in time 3) Clear peaks seen in noise spectra at f > 50 kHz which never have been observed before 4) Noise peak frequencies depend on string location and increase with depth 5) Signal strength in general much smaller than expected from water tests 6) Many transmitter-sensor combinations not seen at all 7) No transmitter signals seen from above 140 m Rolf Nahnhauer IceCube Spring Meeting

4. Future Plans for Analysis A5B5 A5C5 t / 2.5µs t / 2.5 µs Do better signal extraction (fit, first peak only, etc.) Use timing for signal identification Include refraction effects Use Fourier filters for background reduction Take more statistics for averaging +++ many other ideas Rolf Nahnhauer IceCube Spring Meeting

5. Further talks Development & Test of Acoustic Sensors for IceB. Semburg, K. Helbing, T. Karg Status of the Aachen Acoustic Laboratory C. Wiebusch The New Zeuthen Acoustic Test System D. Tosi The Dead Sea for Acoustic Neutrino DetectionD. Cohen Rolf Nahnhauer IceCube Spring Meeting

6. Piezo-ceramic 62.5 kHz resonant frequency Amplifier PUR hard (black colored) Production of HADES T. Karg 2 cm 2 cm Produced by Christopher Naumann at University of Erlangen-Nürnberg.U Erlangen-Nürnberg produces acoustic sensors for ANTARES Rolf Nahnhauer IceCube Spring Meeting

7. 4.5 m 3.0 m 3.5 m Plan C. Wiebusch • Motivation: have a multi-purpose test laboratory for • Verification of the thermo-acoustic effect in ice • Development of acoustical sensors • Calibration of acoustic sensors • Sufficient lab-space and infrastructure available in Aachen. • Two main sites: • Laboratory for sensor development,etc. • Cool room with tank for testing • Central Element: Ice-Top Tank • and FCU(provided from UWgraduate school) • -> arrived in Aachen in March(Thank you Albrecht, Tom, Chris, ....!) Rolf Nahnhauer IceCube Spring Meeting

8. The New Zeuthen Acoustic Test System D. Tosi PC/104 Standard Laboratory PWR supply up to 7 sensors + 7 transmitters ? PC desktop ? + Freezer + Lake + other facilities external IRIG-B signal from IceCube GPS system ET6000 Rolf Nahnhauer IceCube Spring Meeting

9. The Measurement D. Cohen Work by Yizhaq Makovsky Useful advice and help from Justin Thanks to E. Waxman Rolf Nahnhauer IceCube Spring Meeting

10. Acoustic Neutrino Detection Working Group SAC-PAP recommendations , March 2007: xx First wg meeting: Friday, 28th of April , Lake Geneva Group members: Aachen, UC Berkeley, DESY, Gent, Lausanne, Stockholm, Uppsala, Wuppertal + individuals from different labs Convener: RN - for period until spring 2008 IC meeting Rolf Nahnhauer IceCube Spring Meeting

11. Aim of AND working group Combine all efforts from different sites - ideas, money, person-power - for an R&D programme with the goal to prepare part of the basis of a 100 km3 hybrid detector Near Future Plans Deploy one string with improved acoustic technique in next season Build movable pinger for use of transmitting sound from different depths in different IceCube holes to acoustic strings Design deeper acoustic string array for deployment in 2009 (E/L) Do lake ice test at Abisko for studying ice properties in „lab“ Do in-ice calibration of sensors and transmitters Rolf Nahnhauer IceCube Spring Meeting

12. Scenario for 07/08 Deployment Make new string 100 m longer Don‘ t put stations at80 m and 100 m Add stations at 430 m and 500 m Use three upgraded SPATS stations at 250 m, 320 m, 500 m Put loud transmitters at 190 m and 430 m Use 140 m, 190 m,400 m and 430 m for new glaciophones,if available 76 X X New: hole 76, 7th of next season 430 m 500 m Rolf Nahnhauer IceCube Spring Meeting

13. The Global Picture Should not forget the final goal: Build a hybrid optical-radio-acoustic detector of ~ 100 km3 instrumented volume around icecube, ready for operation in ~10 years (2017) Outer boundary conditions require to stay with this time scale BUTPreliminary SPATS results do not allow to go full speed aheadProgramme described will need at least another year How to fight one year delay on an already tough time scale ? - Attract more collaborators - Cooperate better with radio - Do things now, which already can be done (without knowing, if acoustic stays an option) Rolf Nahnhauer IceCube Spring Meeting

14. Do Never Forget the Basic Message for GZK Detection hybrid hybrid hybrid hybrid hybrid Ice only material for three technologies in one detector: optical-radio-acoustic Numerous advantages have been discussed already, will not be repeated here What is the prize of GZK neutrinos? my guess: O(10 Mio $)/piecefor first ~20 pieces Several cheap attempts done in recent years: may have seen one - but never discovered it Rolf Nahnhauer IceCube Spring Meeting